Check out recent Porsche email
03-03-2011, 04:28 PM
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Burning Brakes
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03-03-2011, 08:16 PM
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Drifting
The only email I've gotten recently from PCA was trying to sell me 918 shirts and some new Boxster that's special because it's painted black. Can you copy/paste the paragraph you're talking about?
03-08-2011, 06:05 PM
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Please note: LN Engineering will be closed Wed March 2nd and will re-open Wed March 9th, as we will be in California for the 28th Annual Porsche Lit and Toy Show. Please come and visit our booth!
Looking for our retrofit kits? Click here to skip ahead to the kits.
Looking at buying a used Porsche and concerned about engine failures. Read our "How-to" on Buying a used Porsche Boxster, Cayman, or 911.
What can be done to prevent an IMS failure?
There is no quick or easy fix. Like with many aircooled engines, many get torn down and rebuild BEFORE an engine failure so that engines can get upgraded. Short of a pre-emptive rebuild, the best preventative measures that can be taken are to be religious with your maintenance schedule. But keep reading, there's more that you can do.
What can be done is to change your oil more often. We recommend oil changes for the M96 and later engines (as we do for air-cooled engines) every 5,000 miles or 6 months. If you track your car, you should change the oil after every race weekend or every other event at the bare minimum and should also consider used oil analysis to monitor the health of your engine.
Use a higher viscosity motor oil. There are several Porsche approved oils that are 5w40, rather than Mobil 1 0w40. Use of an oil that isn't API SM-rated with more Zn and P or an oil with moly extreme pressure anti-wear additives may improve engine life. Castrol Syntec 5w40 is an API SL rated oil that carries Porsche approval and is an excellent choice, and easy to get locally. Motul 8100 5w40 is another excellent Porsche approved lubricant. By no means should you use any oil thinner than a 0w40 - do not use 0w30, 5w30, or 10w30 viscosities!
Timken Falex bearing tests tend to indicate increased load capacity and less wear scarring with oils with high levels of moly as documented here and may prolong the IMS bearing life. To learn more about motor oils and which ones might be better for your Boxster, Cayman, or 911 model, click here.
Also, make sure you drive your Porsche as it was intended to be driven! We like to see the revs kept above 2,500 rpm - higher rpms provide better protection than lower rpms for the IMS bearing (more on why this is so further down this page). Just make sure you're engine's warmed up first before putting a large load or high rpms on it!
On a new or remanufactured engine utilizing the revised M97 IMS, the only "preventative" measure that can be taken short of our retrofit kits is to remove the seal off the front of the IMS bearing, to allow for engine oil to lubricate the bearing. Alternatively, you can repack the bearing with a quality synthetic bearing grease and put a new seal (available from any place that sells bearings). This same technique could be applied also to MY97-05 bearings, if found to be in excellent condition, but by this point, the majority of the labor that is required to do an IMS retrofit would have already been spent, so it's a better value to replace rather than solely inspect and reseal the IMS flange.
With proper lubrication and more frequent oil changes, longevity of your original IMS can be greatly extended. Our retrofit kits use ceramic bearings with significantly longer service life and come with seals removed for improved oiling as well.
What can be done to check for a failing bearing?
First of all, there's no need to loose sleep over IMS failures. There are a few simple things that can be done next time you're having your Porsche serviced to give you some peace of mind before you take the plunge and have an IMS retrofit kit installed on your car. First, check the filter for any debris whatsoever. If there is any very small pieces of plastic (bearing seal) and/or any magnetic debris that may also be shiny or appear to sparkle, that's a good sign that the bearing is going bad. Any oil leaks at the rear of the engine should be checked out immediately - it is common to think you have a RMS leak, but in fact, a failing bearing will allow the IMS flange seal to leak. Another thing that can be checked is bank to bank camshaft timing deviation, more so to see if there is fluctuation in timing values when they should be constant. Lastly, any technician who knows what a failing water pump or idler belt bearing sounds like should be able to use a stethoscope to listen to the IMS for similar problems.
Can I replace my IMS bearing?
LN Engineering offers three IMS solutions, two of which can be done without disassebly of the engine while the engine is still in the car:
single row IMS retrofit kit (fits MY02-05 M96 engines including some MY00-01)
dual row IMS retrofit kit (fits MY97-99 M96 engines including some MY00-01)
The last option, our IMS Upgrade, requires engine disassembly and the complete intermediate shaft to be sent in to us to be reconditioned and upgraded with our triple-bearing upgrade. A separate upgrade service is available for the updated M97 IMS as well.
But before proceeding with an IMS Retrofit, you first need to identify which IMS you have!
How do I know which IMS my engine has and what can I do?
The only sure fire method of identifying which IMS your engine has requires you look at the hub flange itself. If you give us a call, we should be able to help you decide in most cases what you need.
All MY97-99 vehicles with their original engines will require a dual row retrofit kit. MY00-01 vehicles may need either a dual row or single row retrofit kit, so you'll need to inspect the flange, as described below to be sure which will be needed. MY02-05 will need a single row retrofit kit, although depending on how late the build date was, there may be some MY05 vehicles with the updated M97 IMS, which is not serviceable, at least without teardown of the engine.
A deep flange will be a single row bearing whereas a shallow flange will be a dual row bearing, as shown below:
Dual row 6204 IMS bearing & shallow flange (left), Single row 6204 IMS bearing & deep flange (right)
Revised Single row 3605 bearing IMS with larger diameter stud and nut configuration.
Method two for identifying what type of IMS bearing you have requires removal of the IMS hub flange. The dual row bearing is easy to identify as it does not have an external circlip used to retain the bearing - it uses an internal snap ring to lock the bearing in place. The models which have a single row bearing are identifiable by an external circlip or lock ring.
Engines replaced or vehicles purchased in or after MY2006 should have the revised, larger single-row IMS bearing, identifiable by a larger 22mm nut in the center of the IMS hub flange. This uses a very large 6305 single-row bearing with a load rating similar to the dual row 6204 bearing compared to the earlier single row 6204 bearing which has about 2/3rds the load rating of the 6305.
Here is a close-up of the single row and double row bearing side by side
Revised Single row 6305 bearing IMS with larger diameter stud and 22mm nut configuration, shown with the hub flange removed. Although the bearing is accessible via a removable circlip, you cannot remove it from the IMS without disassembling the whole engine because the o.d. of the bearing is larger in diameter than the opening in the back of the case.
According to PET, here are the engine numbers for single or double row bearings* up until late 2005 then 2006 and later engines which received a larger, non-servicable single row bearing. *Courtesy of Scott Slauson http://www.softronic.us.
Boxster: Double Row: up to 651 12851 (M96.22) up to 671 11237 (M96.21)
Single Row: from 651 12852 (M96.22) from 671 11238 (M96.21)
996: Double Row: up to 661 14164
Single Row: from 661 14165
HINT: WE DO NOT RECOMMEND RELYING ON ENGINE NUMBERS ALONE TO IDENTIFY WHICH TYPE OF IMS YOU HAVE - IF YOU ARE UNSURE AND IN A HURRY, ORDER ONE OF EACH KIT AND RETURN THE UNUSED ONE. WE'LL WAVE THE RESTOCKING FEE.
Who can replace my IMS bearing?
Check out our dealer listing, including shops capable of doing IMS Retrofits. If your preferred shop is not on the list, print this page out and supply it to them - we'll be happy to answer any questions they may have.
Doing an IMS retrofit procedure isn't much harder than doing an ims flange reseal, so if the shop you're thinking of using has done these procedures (as most that are familiar with Boxster, Cayman, or 911s are), a retrofit kit installation won't be any more difficult.
How do you identify an impending IMS failure?
As you can see in the video above, inspection of the IMS bearing at regular intervals, say whenever an RMS leak is being fixed or installing a clutch, can help in evaluating the condition of your IMS.
There are not many warning signs of an impending IMS failure short of a "death rattle" that occurs as the bearing fails and comes apart. If caught early enough, a leak at the IMS hub flange may be signs of a failing bearing, but can be improperly identified as an RMS leak at times. If doing a rear main seal (RMS), it's recommended to do an IMS retrofit at the same time, as the majority of the labor is identical to that of performing the RMS service.
There are also other failures that get classified as IMS failures, including failure of the chain tensioner for the crankshaft to intermediate shaft chain (for which we offer a billet replacement tensioner blade assembly to replace the weak factory part).
Why do intermediate shafts fail (or rather, why do the bearings fail)?
Thanks to a fellow Porsche Boxster owner who is also a retired bearing engineer who worked for Timken Bearing, we have gained much insight towards the root causes of intermediate shaft failures. Here's the reader's digest version of his bearing analysis and how LN Engineering has used this information in developing its IMS solutions. By their estimates, they figure a 90% survival rate of the bearing used in the IMS at 90,000 miles* - resulting in a staggering 10% failure rate (called the Ll0 life)! *Assuming an average speed of 60mph in top gear.
There are two configurations of intermediate shafts – the major variations are in the drive, where the early have a bicycle chain style sprocket where the later is a gear type sprocket. The other differences are in the intermediate shaft bearing configurations, with three bearing configurations - an early dual row, single row, then final version, with the larger single row bearing.
Both intermediate shaft assemblies use a bearing support visible as a small stud from the exterior of the engine in the center of the IMS hub flange. This stud has a flange that centers and rests on the inboard side of the bearing and torques the inner race to the stationary IMS hub flange. The outer race is allowed to rotate which allows the IMS to rotate. A few problems stem from the support stud which is undercut for an o-ring to keep oil from leaking out of the IMS hub flange. This severely weakens the stud as it is undercut deeper than the threads by a good margin. The main problem stems from the use of a sealed bearing. Although the seals are intended to keep oil out of the IMS tube and keep the permanent lubricant in the bearing, neither happens.
On engines observant of factory recommended long drain intervals, oil heavily laden from fuel or just dirty from too long of drain intervals provides poor lubrication for the IMS bearing. Even .002% water in the oil can reduce bearing life by up to 48%. Higher moisture levels up to 6% can reduce bearing life by up to 83%. Excessive oil temperatures also have a negative effect on bearing life - the life of the permanent lubricant used in these bearings is cut in half by every 18F increase in temperature - from an uncontaminated life of up to 30 years at 86F to a useful life of only 90 days at 212F! This is why the bearing engineer recommended removing the seal and allowing the engine oil to lubricate the bearing, and why frequent changes are so important. Oils high in ZDDP and moly further improve longevity as suggested in the article referenced above. More info about ball bearings can be found here.
Now it gets more technical.... Where the exact reason for IMS failures cannot be known for sure, in the bearing analysis it was noted that bearings used in the IMS position are unusual in that they are double sealed and have outer race rotation. Bearings were found to be void of grease and had light oil in them and wear patterns in the ball grooves indicate marginal lubrication due to the relatively low viscosity of motor oil compared to grease.
In addition, conventional class 1 bearings, like the 52100-series bearing steel used in the factory bearings, is typically only stable to 250F, suffering from fatigue and weakening exposed to elevated engine temperatures that slowly affect the bearing's strength over its lifespan. Attempting to reduce engine coolant operating temperatures directly reduces oil temperatures, further improving bearing life! That's why trying to lower the coolant AND oil temperature is so important!
Computer simulation of the 6204 bearing showed that only three ***** are under load at any given time. Hertz stress is moderate. Lube film thickness is very small. Ideally it should be greater than the worst surface finish. Speed is not high enough to develop an elastohydrodynamic film to overcome surface finish/film issue. Fatigue life is high due to relative light load but with no EHD film there will be metal/metal contact and wear. With only three ***** under load at any one time the unloaded ***** will be dragged around by the ball separator. When a ball leaves the loaded zone it will tend to be driven into the separator pocket.
The engineer’s initial thoughts were that the ball-separator failure led to bearing collapse, but after analysis of said IMS bearings, it would appear that bearing wear/fatigue spalls lead to separator wear and outer race failure. Separator failure and bearing collapse causes catastrophic failure of the mounting bolt(s) and IMS/timing chain components. The first recommendation was to use a bearing without seals and secondly to use a higher viscosity oil (with greater film strength). More frequent changes will also improve lubrication quality. An oil with extreme pressure additives like Moly might also further assist in increasing bearing life. Higher rpms also increases bearing life as this lessens the viscosity requirements of the lubricant to maintain EHD lubrication, also providing a reasonable explanation of the lack of IMS failures in tracked cars or those driven "like they were stolen." Likewise, far more failures are found in engines with low mileage that are garage queens and never driven to their full protential. Further recommendations by the retired Timken engineer are evident in the design of LN Engineering’s IMS upgrade and retrofit kits. Shown below are typical IMS failures:
Worn ball bearings from dual-row 6204 bearing (3.4 996, 75,000 mi)
Worn inner race from dual-row 6204 bearing (3.4 996, 75,000 mi)
Why do some used bearings look normal and others have wear on the outside?
Shown above are three used dual row bearings, all in good condition. A normal bearing shown at far right, as we would expect to find. Note two left bearings have wear on the outside diameter of the bearing. At best, we attribute this to tolerances in the manufacturing of the intermediate shaft itself, measured as ovality, taper, or any other variations that might allow a bearing to actually move and loose its press fit. It may be that part of the issue with failing IMS bearings are that the intermediate shafts themselves are not "all made equal", where some do not have the proper press-fit on the bearing or others do not have the bearings centered in the shaft!
Why doesn't the bearing on the other end of the intermediate shaft fail?
Well, there isn't technically a bearing. The other end of the intermediate shaft rides in a bore of raw aluminum, splash oiled. Earlier aircooled Porsches and even later water-cooled GT2, GT3, and Turbo engines use split plain bearings (actually a VW Type 1 double-thrust camshaft bearing) that are oil fed on both ends of the shaft, with decades of proven reliability.
What kind of bearings do you use for the IMS Upgrade or Retrofit kits?
Based off of the knowledge gained from our bearing analysis of both factory single and double-row IMS bearings and significant research, we've employed a custom ceramic hybrid bearing, featuring precision Japanese-made tool steel races and genuine USA-made Timken sintered silicon nitride ultra-low friction roller *****. We use exclusively ceramic hybrid bearings on both our IMS upgrade and retrofit kits. On average up to thirty times more expensive than conventional steel ball bearings, the benefits far outweigh the cost.
Recent improvements in purity and grain structure have given silicon nitride a high stress fatigue life equal to, or better than, that of bearing steels. Some tests have shown life 3 to 5 times that of M-50 steel. Performs up to 15 times longer in poor lubrication environments (like suggested by the bearing analysis above) as compared to steel.
Other benefits include...
Less maintenance - Due to a minimum level of Adhesive Wear, bearing components and lubricants last much longer, saving you expensive service and repair time.
High Hot Strength - High compressive and flexural strength over a wide temperature range. Lends itself for use to 2200 degrees F.
Low Density - Specific density of 3.2 compared to 7.8 for steel. At high bearing operating speeds, the bearing ***** have a centrifugal force which may exceed the external loads on the bearing. The low density of ceramics can reduce this load considerably.
High Hardness - While bearing steel is in the RC 58-64 hardness range, silicon nitride has a hardness of RC 75-80 and offers excellent wear resistance and resistance to denting or flat-spotting.
Coefficient of Friction - Silicon nitride has a coefficient of friction which is significantly lower, especially under marginal lubrication conditions. It also exhibits better resistance to scuffing and seizing than bearing steel.
Corrosion Resistance - Silicon nitride is unaffected by most common corrosive agents, and is well-suited for use in hot corrosive atmospheres, or where lubricants have been known to attack conventional bearing steels.
What is the IMS Upgrade?
To resolve these known IMS problems, we have engineered our IMS upgrade with a billet chromoly steel hub flange, an increased diameter bearing support/retainer (also manufactured out of chromoly), also providing increased bearing area and dynamic load capacity of almost 5,000 lbs. with our triple bearing - compared to 2200 lbs. for the single, 3060 lbs. for the dual row, and 3650 lbs for the MY06 and later single row. In addition, we use Porsche's revised seal to ensure leak free operation and we permanently seal the ims tube (behind the bearings) to prevent it from filling with oil allowing us to use open bearings for improved cooling and lubrication. Your shaft is returned to you, reconditioned and upgraded - cleaned, assembled, and bench tested. We offer this service for all intermediate shafts MY97 through MY08. LN Engineering offers our machine-in upgrade for early and later style intermediate shafts on an exchange basis or we can upgrade your IMS for $895 plus refundable core charge if on exchange basis. MY06-08 shafts receive a new OE Porsche flange, seal, and IMS, as well as an updated ceramic hybrid bearing and the shaft also goes through the same processes as earlier single and dual row bearing intermediate shafts, receiving single updated larger bearing instead.
By adding extra bearings and substantially strengthening the part, both causes for IMS failures are addressed. Use of our ceramic hybrid bearings further help to improve longevity and reliability. Smaller diameter rear pre-loaded bearings increase outer race velocity, promoting higher film strength and improved EHD lubrication with provided splash engine oil lubrication.
IMS Upgrade shown on both the later gear-type (above) and
earlier (bottom) bicycle-chain style sprocket IMS.
IMS Upgrade shown on M97 intermediate shaft (below)
What is the IMS Retrofit Kit?
Unlike our IMS Upgrade which requires the IMS to be removed from the engine to be machined to accept our revised setup, the single and dual row IMS Retrofit Kits are designed to replace the original bearings with like sizes and with similar load ratings, without engine disassembly, and have been developed in partnership with Flat 6 Innovations, for both single and dual row bearing intermediate shafts.
In a process originally developed, tested and used by Scott Slauson of Softronic, extraction and the replacement of the dual row bearing was found to be possible, involving collapse of the internal wire lock that retains the bearings, requiring great force be applied to the bearing to facilitate extraction. This process can be safely completed using the bearing puller (developed by LN Engineering & Flat 6 Innovations) supplied in our tool kit (sold separately) without any damage to the engine or intermediate shaft.
Above photo courtesy of Wayne Dempsey, Pelican Parts.
Once the bearing is out, you are ready to install the new bearing. One trick to getting the new bearing in is to throw it along with the bearing driver tool in the freezer - this will shrink the bearing approximately .0005", making installation even easier. Additionally, if you inspect the original bearing, you may find signs that the outer race has actually been spinning in the IMS housing. Alternatively, you can measure the housing bore for ovality. If that is the case, use Loctite high-temperature bearing mount sparingly on the outer race of the new bearing, then install. Once the new bearing has been driven in (shown above, using the driver tool shown, right), the new billet hub flange can be installed, best accomplished by using longer bolts to draw the flange into place. At this point, the 12-pt nut that goes on the new, larger diameter bearing support gets torqued. One installed, then you can replace the bolts with the proper microencapsulated bolts and torque.
Shown below is the complete single row bearing IMS retrofit kit. We only supply the highest quality ceramic hybrid bearing currently available, with genuine Timken silicon nitride *****. We recommend scrolling back to the top of this page to learn more about why we have chosen these very expensive bearings over cheaper ones. The single row retrofit kit includes a direct replacement for the factory 6204 series bearing.
On engines with a dual row bearing, significantly greater effort is needed to remove the bearing because there is an internal wire lock that has to be forced to compress before the bearing will come out. This differs from the single row which has an external snap ring that has to be removed first. Our tools and associated procedure allows you to safely remove the dual row bearing without stressing the crankcase or any internal components. Shown below is the dual row bearing IMS retrofit kit. The dual row retrofit kit includes a custom dual row bearing as a replacement for the factory dual row 6204 series bearing, which is now retained with a custom external snap ring or spiro-loc (as shown).
Our kits replace the factory sealed bearing with a new, severe duty custom ceramic hybrid roller ball bearing for reduced friction and superior performance in poorly lubricated operating conditions and replaces the factory IMS flange hub, bearing support, and fastener with a stronger, revised billet chromoly assembly.
The center bearing support also receives an increase in size and no longer is cut for the o-ring that keep engine oil from leaking out of the engine - we have relocated the o-ring to the IMS hub flange for added strength to the center stud & bearing support (comparison between our upgraded bearing support and the OE one shown at right)
What is the cost of the kit and what does it include?
The IMS retrofit kit is $519 for the single-row IMS and $595 for the dual-row IMS. Kits include the new bearing support, flange, bearing, retaining ring, and set of new OE Porsche microencapsulated bolts.
The new and improved IMS "PRO" Retrofit Tool Kit is sold separately for $159 which includes:
bearing puller and adapter for extracting the existing bearing from the original center stud/bearing support (shown above)
bearing driver tool to allow easy installation of the new bearing (shown above)
"Easy Out" adapter to allow extraction of bearing using the LN Engineering bearing puller when and if the center stud/bearing support is broken or breaks during extraction
Crankshaft Pully TDC Lock Pin to secure the engine at the proper position to do an IMS Retrofit
Camshaft lock tools for both early 5-chain and later 3-chain engines (kit includes one ea.)
Due to the extreme value of this kit, it is only available for purchase with any qualifying IMS Retrofit Kit purchase.
"Easy Out" Adapter
5-Chain & 3-Chain Camshaft Locks; TDC Lock Pin
What is the procedure for doing an intermediate shaft bearing retrofit kit?
We do not recommend IMS retrofit kit installation as a do-it-yourself project - installation is best left to your trained independent mechanic or Porsche dealership. That said, typically the job is a billable 10-14 hours and average labor rates around the country are $140/hour. Later Tiptronic 911s require the engine and transmission to be removed together, so expect those cars to be very expensive when it comes time to do an IMS retrofit kit.
Basic instructions are available here in PDF format.
Do you offer support for IMS Retrofit installations?
Beyond basic instruction provided with the retrofit kit itself, support is available from Flat 6 Innovations for a modest fee for do-it-yourselfers or those requiring assistance with troublesome installations.
Does installing an IMS retrofit or doing an IMS Upgrade make my engine immune to an IMS failure?
It's hard to answer that question. Porsche revised the design three times across the MY97 to MY08 M96 engine and eventually decided to eliminate the IMS completely from the new MY09 engines. The design of the IMS itself is subject to flaws that cannot be overcome simply by replacing a bearing. That said, we've put the best bearings we can in our IMS Retrofit Kits and Upgrades to give your M96 the best fighting chance for a long service life. It may be advisable to consider the IMS a service item, like a timing belt in many modern cars. Seeing that we're just starting to see more MY05 engines with IMS failures in late 2009, that may suggest that bearing replacement (or inspection at bare minimum) should be considered every four years or 50,000 miles to 5 years or 60,000 miles, similar to many manufacturers' powertrain warranties.
Do you offer a warranty?
Yes, but only on IMS Upgrades or Retrofit kits purchased through and installed by authorized dealers. We will match the authorized dealer's warranty up to 12 months/12,000 mi on an intermediate shaft that has received the IMS Upgrade or on a Retrofit kit installed as preventative maintenance. Due to our inability to control the circumstances of an IMS Retrofit installation, there is no warranty on this product if a retrofit kit is being installed in place of a failed IMS bearing. Warranty form comes with your IMS retrofit kit with terms and conditions of limited warranty.
Should I get an extended warranty?
Considering the high cost of engine replacement, many would think that an extended warranty is a must, but as these cars age, many have provisions where they will not pay out more than the wholesale value of a vehicle or may have provisions where lubrication related failures are exclusions, leaving a big hole in your coverage. Be sure to check that any policy you do get is backed by the dealer you are purchasing it from (in case they don't pay up) or is sold by a reputable company, like Paragon Motor Club, who resells only trusted and safe extended warranty policies. Similarly, coverage by your auto insurance provider also is a safe choice - one such company in Mercury Insurance, which underwrites their own extended warranties and is a safe bet that you won't be left out to dry on a claim. Do your research before buying any policy, that's for sure! Google and the BBB are your friends.
What happens if I've already had an intermediate shaft failure?
Depending on how bad of a failure your engine has suffered, it may still be possible to extract the failed bearing and install a retrofit kit. Our retrofit kits are intended for preventative maintenance or fixing of bearings in the process of failing with excess wear, but that haven't yet failed.
If the original center stud / bearing support has broken, you'll need our "Easy Out" adapter, which is part of the IMS Pro Tool Kit.
If the inner race has failed and the ***** have come out of the bearing, damaging the IMS (as shown below), we do not recommend doing the IMS retrofit procedure. This typically is the case with most single row IMS bearing failures, as this damage typically destroys the snap ring groove, preventing you to install a new snap ring to retain the new bearing.
The aftermath of a single row IMS bearing failure on a MY04 - complete disassembly and a rebuild is your only recourse at this point. Also, when damage is this extensive, installation of an IMS retrofit is not possible and the shaft itself is not usable. The engine will need to be torn down and alternate core IMS sourced (we offer rebuild cores, check with us on availability).
Although it is possible to pull the bearing from the outer race using a Kukko 22-2 counterstay and 21-6 internal extractor or use extreme methods to get the failed bearing out, at this point a significant amount of debris has gone through the engine and there is also the high probability that the drive gear/sprocket will have moved and is backing off the shaft, possibly leading to other problems down the road.
Make sure that you do not pull directly on the back of the case when using any Kukko counterstays. You'll want to fabricate some sort of bushing to go in and apply the force of extracting the bearing directly on the IMS housing. Shown below is the bearing bushing tool LN Engineering previously sold. Limited quantities are available for purchase to be used with the aforementioned Kukko products.
The aftermath of a dual row IMS bearing failure - complete disassembly and a rebuild is your only recourse at this point. photo courtesy of Renntech.
Do you offer an upgraded oil pump drive?
Yes, we now offer a heat treated chromoly oil pump hex drive to replace the cheap factory pump drive, which has known to fail, shearing in two, resulting in a catastrophic loss of oil pressure.
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2011 Pricing Schedule
Description Price
IMS Upgrade
sold on an exchange basis or send in your dual row
or single row bearing m96 intermediate shaft $895
IMS Upgrade
for 2006 and later updated m97 intermediate shafts $762.83
Chromoly Oil Pump Drive
Heat Treated 4140 Chromoly OIl Pump Dirve $19.95
IMS Retrofit
for single-row bearing intermediate shaft $519
IMS Retrofit
for dual-row bearing intermediate shaft $595
LN Engineering IMS Pro Tool Kit
includes bearing puller, bearing driver, cam locks, tdc lock pin, and "easy out" adapter $159
Complete LN Engineering product and price listing available here in pdf format.
As a leader in the Porsche community, LN Engineering's focus on quality, service, and support is evident, and begins with you. Let us help you succeed.
Contact us at 815-472-2939 or info@LNengineering.com to
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Warranty and Disclaimer
Looking for our retrofit kits? Click here to skip ahead to the kits.
Looking at buying a used Porsche and concerned about engine failures. Read our "How-to" on Buying a used Porsche Boxster, Cayman, or 911.
What can be done to prevent an IMS failure?
There is no quick or easy fix. Like with many aircooled engines, many get torn down and rebuild BEFORE an engine failure so that engines can get upgraded. Short of a pre-emptive rebuild, the best preventative measures that can be taken are to be religious with your maintenance schedule. But keep reading, there's more that you can do.
What can be done is to change your oil more often. We recommend oil changes for the M96 and later engines (as we do for air-cooled engines) every 5,000 miles or 6 months. If you track your car, you should change the oil after every race weekend or every other event at the bare minimum and should also consider used oil analysis to monitor the health of your engine.
Use a higher viscosity motor oil. There are several Porsche approved oils that are 5w40, rather than Mobil 1 0w40. Use of an oil that isn't API SM-rated with more Zn and P or an oil with moly extreme pressure anti-wear additives may improve engine life. Castrol Syntec 5w40 is an API SL rated oil that carries Porsche approval and is an excellent choice, and easy to get locally. Motul 8100 5w40 is another excellent Porsche approved lubricant. By no means should you use any oil thinner than a 0w40 - do not use 0w30, 5w30, or 10w30 viscosities!
Timken Falex bearing tests tend to indicate increased load capacity and less wear scarring with oils with high levels of moly as documented here and may prolong the IMS bearing life. To learn more about motor oils and which ones might be better for your Boxster, Cayman, or 911 model, click here.
Also, make sure you drive your Porsche as it was intended to be driven! We like to see the revs kept above 2,500 rpm - higher rpms provide better protection than lower rpms for the IMS bearing (more on why this is so further down this page). Just make sure you're engine's warmed up first before putting a large load or high rpms on it!
On a new or remanufactured engine utilizing the revised M97 IMS, the only "preventative" measure that can be taken short of our retrofit kits is to remove the seal off the front of the IMS bearing, to allow for engine oil to lubricate the bearing. Alternatively, you can repack the bearing with a quality synthetic bearing grease and put a new seal (available from any place that sells bearings). This same technique could be applied also to MY97-05 bearings, if found to be in excellent condition, but by this point, the majority of the labor that is required to do an IMS retrofit would have already been spent, so it's a better value to replace rather than solely inspect and reseal the IMS flange.
With proper lubrication and more frequent oil changes, longevity of your original IMS can be greatly extended. Our retrofit kits use ceramic bearings with significantly longer service life and come with seals removed for improved oiling as well.
What can be done to check for a failing bearing?
First of all, there's no need to loose sleep over IMS failures. There are a few simple things that can be done next time you're having your Porsche serviced to give you some peace of mind before you take the plunge and have an IMS retrofit kit installed on your car. First, check the filter for any debris whatsoever. If there is any very small pieces of plastic (bearing seal) and/or any magnetic debris that may also be shiny or appear to sparkle, that's a good sign that the bearing is going bad. Any oil leaks at the rear of the engine should be checked out immediately - it is common to think you have a RMS leak, but in fact, a failing bearing will allow the IMS flange seal to leak. Another thing that can be checked is bank to bank camshaft timing deviation, more so to see if there is fluctuation in timing values when they should be constant. Lastly, any technician who knows what a failing water pump or idler belt bearing sounds like should be able to use a stethoscope to listen to the IMS for similar problems.
Can I replace my IMS bearing?
LN Engineering offers three IMS solutions, two of which can be done without disassebly of the engine while the engine is still in the car:
single row IMS retrofit kit (fits MY02-05 M96 engines including some MY00-01)
dual row IMS retrofit kit (fits MY97-99 M96 engines including some MY00-01)
The last option, our IMS Upgrade, requires engine disassembly and the complete intermediate shaft to be sent in to us to be reconditioned and upgraded with our triple-bearing upgrade. A separate upgrade service is available for the updated M97 IMS as well.
But before proceeding with an IMS Retrofit, you first need to identify which IMS you have!
How do I know which IMS my engine has and what can I do?
The only sure fire method of identifying which IMS your engine has requires you look at the hub flange itself. If you give us a call, we should be able to help you decide in most cases what you need.
All MY97-99 vehicles with their original engines will require a dual row retrofit kit. MY00-01 vehicles may need either a dual row or single row retrofit kit, so you'll need to inspect the flange, as described below to be sure which will be needed. MY02-05 will need a single row retrofit kit, although depending on how late the build date was, there may be some MY05 vehicles with the updated M97 IMS, which is not serviceable, at least without teardown of the engine.
A deep flange will be a single row bearing whereas a shallow flange will be a dual row bearing, as shown below:
Dual row 6204 IMS bearing & shallow flange (left), Single row 6204 IMS bearing & deep flange (right)
Revised Single row 3605 bearing IMS with larger diameter stud and nut configuration.
Method two for identifying what type of IMS bearing you have requires removal of the IMS hub flange. The dual row bearing is easy to identify as it does not have an external circlip used to retain the bearing - it uses an internal snap ring to lock the bearing in place. The models which have a single row bearing are identifiable by an external circlip or lock ring.
Engines replaced or vehicles purchased in or after MY2006 should have the revised, larger single-row IMS bearing, identifiable by a larger 22mm nut in the center of the IMS hub flange. This uses a very large 6305 single-row bearing with a load rating similar to the dual row 6204 bearing compared to the earlier single row 6204 bearing which has about 2/3rds the load rating of the 6305.
Here is a close-up of the single row and double row bearing side by side
Revised Single row 6305 bearing IMS with larger diameter stud and 22mm nut configuration, shown with the hub flange removed. Although the bearing is accessible via a removable circlip, you cannot remove it from the IMS without disassembling the whole engine because the o.d. of the bearing is larger in diameter than the opening in the back of the case.
According to PET, here are the engine numbers for single or double row bearings* up until late 2005 then 2006 and later engines which received a larger, non-servicable single row bearing. *Courtesy of Scott Slauson http://www.softronic.us.
Boxster: Double Row: up to 651 12851 (M96.22) up to 671 11237 (M96.21)
Single Row: from 651 12852 (M96.22) from 671 11238 (M96.21)
996: Double Row: up to 661 14164
Single Row: from 661 14165
HINT: WE DO NOT RECOMMEND RELYING ON ENGINE NUMBERS ALONE TO IDENTIFY WHICH TYPE OF IMS YOU HAVE - IF YOU ARE UNSURE AND IN A HURRY, ORDER ONE OF EACH KIT AND RETURN THE UNUSED ONE. WE'LL WAVE THE RESTOCKING FEE.
Who can replace my IMS bearing?
Check out our dealer listing, including shops capable of doing IMS Retrofits. If your preferred shop is not on the list, print this page out and supply it to them - we'll be happy to answer any questions they may have.
Doing an IMS retrofit procedure isn't much harder than doing an ims flange reseal, so if the shop you're thinking of using has done these procedures (as most that are familiar with Boxster, Cayman, or 911s are), a retrofit kit installation won't be any more difficult.
How do you identify an impending IMS failure?
As you can see in the video above, inspection of the IMS bearing at regular intervals, say whenever an RMS leak is being fixed or installing a clutch, can help in evaluating the condition of your IMS.
There are not many warning signs of an impending IMS failure short of a "death rattle" that occurs as the bearing fails and comes apart. If caught early enough, a leak at the IMS hub flange may be signs of a failing bearing, but can be improperly identified as an RMS leak at times. If doing a rear main seal (RMS), it's recommended to do an IMS retrofit at the same time, as the majority of the labor is identical to that of performing the RMS service.
There are also other failures that get classified as IMS failures, including failure of the chain tensioner for the crankshaft to intermediate shaft chain (for which we offer a billet replacement tensioner blade assembly to replace the weak factory part).
Why do intermediate shafts fail (or rather, why do the bearings fail)?
Thanks to a fellow Porsche Boxster owner who is also a retired bearing engineer who worked for Timken Bearing, we have gained much insight towards the root causes of intermediate shaft failures. Here's the reader's digest version of his bearing analysis and how LN Engineering has used this information in developing its IMS solutions. By their estimates, they figure a 90% survival rate of the bearing used in the IMS at 90,000 miles* - resulting in a staggering 10% failure rate (called the Ll0 life)! *Assuming an average speed of 60mph in top gear.
There are two configurations of intermediate shafts – the major variations are in the drive, where the early have a bicycle chain style sprocket where the later is a gear type sprocket. The other differences are in the intermediate shaft bearing configurations, with three bearing configurations - an early dual row, single row, then final version, with the larger single row bearing.
Both intermediate shaft assemblies use a bearing support visible as a small stud from the exterior of the engine in the center of the IMS hub flange. This stud has a flange that centers and rests on the inboard side of the bearing and torques the inner race to the stationary IMS hub flange. The outer race is allowed to rotate which allows the IMS to rotate. A few problems stem from the support stud which is undercut for an o-ring to keep oil from leaking out of the IMS hub flange. This severely weakens the stud as it is undercut deeper than the threads by a good margin. The main problem stems from the use of a sealed bearing. Although the seals are intended to keep oil out of the IMS tube and keep the permanent lubricant in the bearing, neither happens.
On engines observant of factory recommended long drain intervals, oil heavily laden from fuel or just dirty from too long of drain intervals provides poor lubrication for the IMS bearing. Even .002% water in the oil can reduce bearing life by up to 48%. Higher moisture levels up to 6% can reduce bearing life by up to 83%. Excessive oil temperatures also have a negative effect on bearing life - the life of the permanent lubricant used in these bearings is cut in half by every 18F increase in temperature - from an uncontaminated life of up to 30 years at 86F to a useful life of only 90 days at 212F! This is why the bearing engineer recommended removing the seal and allowing the engine oil to lubricate the bearing, and why frequent changes are so important. Oils high in ZDDP and moly further improve longevity as suggested in the article referenced above. More info about ball bearings can be found here.
Now it gets more technical.... Where the exact reason for IMS failures cannot be known for sure, in the bearing analysis it was noted that bearings used in the IMS position are unusual in that they are double sealed and have outer race rotation. Bearings were found to be void of grease and had light oil in them and wear patterns in the ball grooves indicate marginal lubrication due to the relatively low viscosity of motor oil compared to grease.
In addition, conventional class 1 bearings, like the 52100-series bearing steel used in the factory bearings, is typically only stable to 250F, suffering from fatigue and weakening exposed to elevated engine temperatures that slowly affect the bearing's strength over its lifespan. Attempting to reduce engine coolant operating temperatures directly reduces oil temperatures, further improving bearing life! That's why trying to lower the coolant AND oil temperature is so important!
Computer simulation of the 6204 bearing showed that only three ***** are under load at any given time. Hertz stress is moderate. Lube film thickness is very small. Ideally it should be greater than the worst surface finish. Speed is not high enough to develop an elastohydrodynamic film to overcome surface finish/film issue. Fatigue life is high due to relative light load but with no EHD film there will be metal/metal contact and wear. With only three ***** under load at any one time the unloaded ***** will be dragged around by the ball separator. When a ball leaves the loaded zone it will tend to be driven into the separator pocket.
The engineer’s initial thoughts were that the ball-separator failure led to bearing collapse, but after analysis of said IMS bearings, it would appear that bearing wear/fatigue spalls lead to separator wear and outer race failure. Separator failure and bearing collapse causes catastrophic failure of the mounting bolt(s) and IMS/timing chain components. The first recommendation was to use a bearing without seals and secondly to use a higher viscosity oil (with greater film strength). More frequent changes will also improve lubrication quality. An oil with extreme pressure additives like Moly might also further assist in increasing bearing life. Higher rpms also increases bearing life as this lessens the viscosity requirements of the lubricant to maintain EHD lubrication, also providing a reasonable explanation of the lack of IMS failures in tracked cars or those driven "like they were stolen." Likewise, far more failures are found in engines with low mileage that are garage queens and never driven to their full protential. Further recommendations by the retired Timken engineer are evident in the design of LN Engineering’s IMS upgrade and retrofit kits. Shown below are typical IMS failures:
Worn ball bearings from dual-row 6204 bearing (3.4 996, 75,000 mi)
Worn inner race from dual-row 6204 bearing (3.4 996, 75,000 mi)
Why do some used bearings look normal and others have wear on the outside?
Shown above are three used dual row bearings, all in good condition. A normal bearing shown at far right, as we would expect to find. Note two left bearings have wear on the outside diameter of the bearing. At best, we attribute this to tolerances in the manufacturing of the intermediate shaft itself, measured as ovality, taper, or any other variations that might allow a bearing to actually move and loose its press fit. It may be that part of the issue with failing IMS bearings are that the intermediate shafts themselves are not "all made equal", where some do not have the proper press-fit on the bearing or others do not have the bearings centered in the shaft!
Why doesn't the bearing on the other end of the intermediate shaft fail?
Well, there isn't technically a bearing. The other end of the intermediate shaft rides in a bore of raw aluminum, splash oiled. Earlier aircooled Porsches and even later water-cooled GT2, GT3, and Turbo engines use split plain bearings (actually a VW Type 1 double-thrust camshaft bearing) that are oil fed on both ends of the shaft, with decades of proven reliability.
What kind of bearings do you use for the IMS Upgrade or Retrofit kits?
Based off of the knowledge gained from our bearing analysis of both factory single and double-row IMS bearings and significant research, we've employed a custom ceramic hybrid bearing, featuring precision Japanese-made tool steel races and genuine USA-made Timken sintered silicon nitride ultra-low friction roller *****. We use exclusively ceramic hybrid bearings on both our IMS upgrade and retrofit kits. On average up to thirty times more expensive than conventional steel ball bearings, the benefits far outweigh the cost.
Recent improvements in purity and grain structure have given silicon nitride a high stress fatigue life equal to, or better than, that of bearing steels. Some tests have shown life 3 to 5 times that of M-50 steel. Performs up to 15 times longer in poor lubrication environments (like suggested by the bearing analysis above) as compared to steel.
Other benefits include...
Less maintenance - Due to a minimum level of Adhesive Wear, bearing components and lubricants last much longer, saving you expensive service and repair time.
High Hot Strength - High compressive and flexural strength over a wide temperature range. Lends itself for use to 2200 degrees F.
Low Density - Specific density of 3.2 compared to 7.8 for steel. At high bearing operating speeds, the bearing ***** have a centrifugal force which may exceed the external loads on the bearing. The low density of ceramics can reduce this load considerably.
High Hardness - While bearing steel is in the RC 58-64 hardness range, silicon nitride has a hardness of RC 75-80 and offers excellent wear resistance and resistance to denting or flat-spotting.
Coefficient of Friction - Silicon nitride has a coefficient of friction which is significantly lower, especially under marginal lubrication conditions. It also exhibits better resistance to scuffing and seizing than bearing steel.
Corrosion Resistance - Silicon nitride is unaffected by most common corrosive agents, and is well-suited for use in hot corrosive atmospheres, or where lubricants have been known to attack conventional bearing steels.
What is the IMS Upgrade?
To resolve these known IMS problems, we have engineered our IMS upgrade with a billet chromoly steel hub flange, an increased diameter bearing support/retainer (also manufactured out of chromoly), also providing increased bearing area and dynamic load capacity of almost 5,000 lbs. with our triple bearing - compared to 2200 lbs. for the single, 3060 lbs. for the dual row, and 3650 lbs for the MY06 and later single row. In addition, we use Porsche's revised seal to ensure leak free operation and we permanently seal the ims tube (behind the bearings) to prevent it from filling with oil allowing us to use open bearings for improved cooling and lubrication. Your shaft is returned to you, reconditioned and upgraded - cleaned, assembled, and bench tested. We offer this service for all intermediate shafts MY97 through MY08. LN Engineering offers our machine-in upgrade for early and later style intermediate shafts on an exchange basis or we can upgrade your IMS for $895 plus refundable core charge if on exchange basis. MY06-08 shafts receive a new OE Porsche flange, seal, and IMS, as well as an updated ceramic hybrid bearing and the shaft also goes through the same processes as earlier single and dual row bearing intermediate shafts, receiving single updated larger bearing instead.
By adding extra bearings and substantially strengthening the part, both causes for IMS failures are addressed. Use of our ceramic hybrid bearings further help to improve longevity and reliability. Smaller diameter rear pre-loaded bearings increase outer race velocity, promoting higher film strength and improved EHD lubrication with provided splash engine oil lubrication.
IMS Upgrade shown on both the later gear-type (above) and
earlier (bottom) bicycle-chain style sprocket IMS.
IMS Upgrade shown on M97 intermediate shaft (below)
What is the IMS Retrofit Kit?
Unlike our IMS Upgrade which requires the IMS to be removed from the engine to be machined to accept our revised setup, the single and dual row IMS Retrofit Kits are designed to replace the original bearings with like sizes and with similar load ratings, without engine disassembly, and have been developed in partnership with Flat 6 Innovations, for both single and dual row bearing intermediate shafts.
In a process originally developed, tested and used by Scott Slauson of Softronic, extraction and the replacement of the dual row bearing was found to be possible, involving collapse of the internal wire lock that retains the bearings, requiring great force be applied to the bearing to facilitate extraction. This process can be safely completed using the bearing puller (developed by LN Engineering & Flat 6 Innovations) supplied in our tool kit (sold separately) without any damage to the engine or intermediate shaft.
Above photo courtesy of Wayne Dempsey, Pelican Parts.
Once the bearing is out, you are ready to install the new bearing. One trick to getting the new bearing in is to throw it along with the bearing driver tool in the freezer - this will shrink the bearing approximately .0005", making installation even easier. Additionally, if you inspect the original bearing, you may find signs that the outer race has actually been spinning in the IMS housing. Alternatively, you can measure the housing bore for ovality. If that is the case, use Loctite high-temperature bearing mount sparingly on the outer race of the new bearing, then install. Once the new bearing has been driven in (shown above, using the driver tool shown, right), the new billet hub flange can be installed, best accomplished by using longer bolts to draw the flange into place. At this point, the 12-pt nut that goes on the new, larger diameter bearing support gets torqued. One installed, then you can replace the bolts with the proper microencapsulated bolts and torque.
Shown below is the complete single row bearing IMS retrofit kit. We only supply the highest quality ceramic hybrid bearing currently available, with genuine Timken silicon nitride *****. We recommend scrolling back to the top of this page to learn more about why we have chosen these very expensive bearings over cheaper ones. The single row retrofit kit includes a direct replacement for the factory 6204 series bearing.
On engines with a dual row bearing, significantly greater effort is needed to remove the bearing because there is an internal wire lock that has to be forced to compress before the bearing will come out. This differs from the single row which has an external snap ring that has to be removed first. Our tools and associated procedure allows you to safely remove the dual row bearing without stressing the crankcase or any internal components. Shown below is the dual row bearing IMS retrofit kit. The dual row retrofit kit includes a custom dual row bearing as a replacement for the factory dual row 6204 series bearing, which is now retained with a custom external snap ring or spiro-loc (as shown).
Our kits replace the factory sealed bearing with a new, severe duty custom ceramic hybrid roller ball bearing for reduced friction and superior performance in poorly lubricated operating conditions and replaces the factory IMS flange hub, bearing support, and fastener with a stronger, revised billet chromoly assembly.
The center bearing support also receives an increase in size and no longer is cut for the o-ring that keep engine oil from leaking out of the engine - we have relocated the o-ring to the IMS hub flange for added strength to the center stud & bearing support (comparison between our upgraded bearing support and the OE one shown at right)
What is the cost of the kit and what does it include?
The IMS retrofit kit is $519 for the single-row IMS and $595 for the dual-row IMS. Kits include the new bearing support, flange, bearing, retaining ring, and set of new OE Porsche microencapsulated bolts.
The new and improved IMS "PRO" Retrofit Tool Kit is sold separately for $159 which includes:
bearing puller and adapter for extracting the existing bearing from the original center stud/bearing support (shown above)
bearing driver tool to allow easy installation of the new bearing (shown above)
"Easy Out" adapter to allow extraction of bearing using the LN Engineering bearing puller when and if the center stud/bearing support is broken or breaks during extraction
Crankshaft Pully TDC Lock Pin to secure the engine at the proper position to do an IMS Retrofit
Camshaft lock tools for both early 5-chain and later 3-chain engines (kit includes one ea.)
Due to the extreme value of this kit, it is only available for purchase with any qualifying IMS Retrofit Kit purchase.
"Easy Out" Adapter
5-Chain & 3-Chain Camshaft Locks; TDC Lock Pin
What is the procedure for doing an intermediate shaft bearing retrofit kit?
We do not recommend IMS retrofit kit installation as a do-it-yourself project - installation is best left to your trained independent mechanic or Porsche dealership. That said, typically the job is a billable 10-14 hours and average labor rates around the country are $140/hour. Later Tiptronic 911s require the engine and transmission to be removed together, so expect those cars to be very expensive when it comes time to do an IMS retrofit kit.
Basic instructions are available here in PDF format.
Do you offer support for IMS Retrofit installations?
Beyond basic instruction provided with the retrofit kit itself, support is available from Flat 6 Innovations for a modest fee for do-it-yourselfers or those requiring assistance with troublesome installations.
Does installing an IMS retrofit or doing an IMS Upgrade make my engine immune to an IMS failure?
It's hard to answer that question. Porsche revised the design three times across the MY97 to MY08 M96 engine and eventually decided to eliminate the IMS completely from the new MY09 engines. The design of the IMS itself is subject to flaws that cannot be overcome simply by replacing a bearing. That said, we've put the best bearings we can in our IMS Retrofit Kits and Upgrades to give your M96 the best fighting chance for a long service life. It may be advisable to consider the IMS a service item, like a timing belt in many modern cars. Seeing that we're just starting to see more MY05 engines with IMS failures in late 2009, that may suggest that bearing replacement (or inspection at bare minimum) should be considered every four years or 50,000 miles to 5 years or 60,000 miles, similar to many manufacturers' powertrain warranties.
Do you offer a warranty?
Yes, but only on IMS Upgrades or Retrofit kits purchased through and installed by authorized dealers. We will match the authorized dealer's warranty up to 12 months/12,000 mi on an intermediate shaft that has received the IMS Upgrade or on a Retrofit kit installed as preventative maintenance. Due to our inability to control the circumstances of an IMS Retrofit installation, there is no warranty on this product if a retrofit kit is being installed in place of a failed IMS bearing. Warranty form comes with your IMS retrofit kit with terms and conditions of limited warranty.
Should I get an extended warranty?
Considering the high cost of engine replacement, many would think that an extended warranty is a must, but as these cars age, many have provisions where they will not pay out more than the wholesale value of a vehicle or may have provisions where lubrication related failures are exclusions, leaving a big hole in your coverage. Be sure to check that any policy you do get is backed by the dealer you are purchasing it from (in case they don't pay up) or is sold by a reputable company, like Paragon Motor Club, who resells only trusted and safe extended warranty policies. Similarly, coverage by your auto insurance provider also is a safe choice - one such company in Mercury Insurance, which underwrites their own extended warranties and is a safe bet that you won't be left out to dry on a claim. Do your research before buying any policy, that's for sure! Google and the BBB are your friends.
What happens if I've already had an intermediate shaft failure?
Depending on how bad of a failure your engine has suffered, it may still be possible to extract the failed bearing and install a retrofit kit. Our retrofit kits are intended for preventative maintenance or fixing of bearings in the process of failing with excess wear, but that haven't yet failed.
If the original center stud / bearing support has broken, you'll need our "Easy Out" adapter, which is part of the IMS Pro Tool Kit.
If the inner race has failed and the ***** have come out of the bearing, damaging the IMS (as shown below), we do not recommend doing the IMS retrofit procedure. This typically is the case with most single row IMS bearing failures, as this damage typically destroys the snap ring groove, preventing you to install a new snap ring to retain the new bearing.
The aftermath of a single row IMS bearing failure on a MY04 - complete disassembly and a rebuild is your only recourse at this point. Also, when damage is this extensive, installation of an IMS retrofit is not possible and the shaft itself is not usable. The engine will need to be torn down and alternate core IMS sourced (we offer rebuild cores, check with us on availability).
Although it is possible to pull the bearing from the outer race using a Kukko 22-2 counterstay and 21-6 internal extractor or use extreme methods to get the failed bearing out, at this point a significant amount of debris has gone through the engine and there is also the high probability that the drive gear/sprocket will have moved and is backing off the shaft, possibly leading to other problems down the road.
Make sure that you do not pull directly on the back of the case when using any Kukko counterstays. You'll want to fabricate some sort of bushing to go in and apply the force of extracting the bearing directly on the IMS housing. Shown below is the bearing bushing tool LN Engineering previously sold. Limited quantities are available for purchase to be used with the aforementioned Kukko products.
The aftermath of a dual row IMS bearing failure - complete disassembly and a rebuild is your only recourse at this point. photo courtesy of Renntech.
Do you offer an upgraded oil pump drive?
Yes, we now offer a heat treated chromoly oil pump hex drive to replace the cheap factory pump drive, which has known to fail, shearing in two, resulting in a catastrophic loss of oil pressure.
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--------------------------------------------------------------------------------
2011 Pricing Schedule
Description Price
IMS Upgrade
sold on an exchange basis or send in your dual row
or single row bearing m96 intermediate shaft $895
IMS Upgrade
for 2006 and later updated m97 intermediate shafts $762.83
Chromoly Oil Pump Drive
Heat Treated 4140 Chromoly OIl Pump Dirve $19.95
IMS Retrofit
for single-row bearing intermediate shaft $519
IMS Retrofit
for dual-row bearing intermediate shaft $595
LN Engineering IMS Pro Tool Kit
includes bearing puller, bearing driver, cam locks, tdc lock pin, and "easy out" adapter $159
Complete LN Engineering product and price listing available here in pdf format.
As a leader in the Porsche community, LN Engineering's focus on quality, service, and support is evident, and begins with you. Let us help you succeed.
Contact us at 815-472-2939 or info@LNengineering.com to
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Warranty and Disclaimer
Trending Topics
03-08-2011, 08:36 PM
#8
Drifting
Wow, that's an awesome writeup! I think I can summarize it for everyone:
DRIVE! There's no excuse left! If you're not bouncing the tach off the rev limited at least 3 times in rapid succession every time you drive it, you're destroying your IMS!
Higher rpms also increases bearing life as this lessens the viscosity requirements of the lubricant to maintain EHD lubrication, also providing a reasonable explanation of the lack of IMS failures in tracked cars or those driven "like they were stolen." Likewise, far more failures are found in engines with low mileage that are garage queens and never driven to their full protential.
03-09-2011, 03:02 PM
#9
LOl There just may be a middle ground between lugging the engine and running it at redline.
03-10-2011, 11:37 AM
#10
Burning Brakes
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Higher rpms also increases bearing life as this lessens the viscosity requirements of the lubricant to maintain EHD lubrication, also providing a reasonable explanation of the lack of IMS failures in tracked cars or those driven "like they were stolen." Likewise, far more failures are found in engines with low mileage that are garage queens and never driven to their full potential.
03-11-2011, 03:30 PM
#11
Drifting
Plus, you paid for the whole engine, not just half of it. Might as well use & enjoy it to its full potential, right?
Last edited by sjfehr; 03-13-2011 at 06:20 PM.
03-11-2011, 06:41 PM
#12
Burning Brakes
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lus, you paid for the whole engine, not just have of it. Might as well use & enjoy it to its full potential, right?
03-13-2011, 04:38 PM
#13
The two examples he cited- tracked cars and "driven like they were stolen" are run right up to the redline. These engines are built for it, there's nothing wrong with it.
Plus, you paid for the whole engine, not just have of it. Might as well use & enjoy it to its full potential, right?
Plus, you paid for the whole engine, not just have of it. Might as well use & enjoy it to its full potential, right?
03-14-2011, 11:29 AM
#14
Burning Brakes
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I spoke with today at L&N whose background is Chemical engineering. She said to go with 5 - 40 and to get away from mobil-1. Also confirmed, despite the oil change only being 3,000 miles ago, having sat the winter, should be dumped.