The IMS discussion thread (Read this first!)
Nordschleife Master
Joined: May 2005
Posts: 7,326
Likes: 77
Former Vendor
Joined: Nov 2010
Posts: 6,968
Likes: 2,342
From: Cleveland Georgia
The M96.01 can have either the duplex style chain, or the internal tooth type chain. The change between these occurred part way through the M96.01 manufacturing.
Yes, you will need the correct crank, and IMS. The internal tooth type IMS assemblies are the hardest to find. Most were equipped with single row bearings, and have since died.
As far as the IMS snap rings, they are not all the same. The units that are offered with LN kits are manufactured specifically for those kits. Always source your support pieces from the provider of the kit, you never want to mix and match.
Yes, you will need the correct crank, and IMS. The internal tooth type IMS assemblies are the hardest to find. Most were equipped with single row bearings, and have since died.
As far as the IMS snap rings, they are not all the same. The units that are offered with LN kits are manufactured specifically for those kits. Always source your support pieces from the provider of the kit, you never want to mix and match.
Nordschleife Master
Joined: May 2005
Posts: 7,326
Likes: 77
Oh I see. Learned something new. I always thought the internal tooth type IMS wasn't introduced till later.
The M96.01 can have either the duplex style chain, or the internal tooth type chain. The change between these occurred part way through the M96.01 manufacturing.
Yes, you will need the correct crank, and IMS. The internal tooth type IMS assemblies are the hardest to find. Most were equipped with single row bearings, and have since died.
As far as the IMS snap rings, they are not all the same. The units that are offered with LN kits are manufactured specifically for those kits. Always source your support pieces from the provider of the kit, you never want to mix and match.
Yes, you will need the correct crank, and IMS. The internal tooth type IMS assemblies are the hardest to find. Most were equipped with single row bearings, and have since died.
As far as the IMS snap rings, they are not all the same. The units that are offered with LN kits are manufactured specifically for those kits. Always source your support pieces from the provider of the kit, you never want to mix and match.
Rennlist Member
Joined: Mar 2004
Posts: 1,285
Likes: 374
From: L.A. USA
The M96.01 can have either the duplex style chain, or the internal tooth type chain. The change between these occurred part way through the M96.01 manufacturing.
Yes, you will need the correct crank, and IMS. The internal tooth type IMS assemblies are the hardest to find. Most were equipped with single row bearings, and have since died.
As far as the IMS snap rings, they are not all the same. The units that are offered with LN kits are manufactured specifically for those kits. Always source your support pieces from the provider of the kit, you never want to mix and match.
Yes, you will need the correct crank, and IMS. The internal tooth type IMS assemblies are the hardest to find. Most were equipped with single row bearings, and have since died.
As far as the IMS snap rings, they are not all the same. The units that are offered with LN kits are manufactured specifically for those kits. Always source your support pieces from the provider of the kit, you never want to mix and match.
Last edited by MoeMonney; Jul 6, 2016 at 06:17 AM.
Nordschleife Master
Joined: May 2005
Posts: 7,326
Likes: 77
No, I think you are fine. The point was the crank of the internal chain type is different than the crank of the duplex chain type. Your engine ran before so obviously your crank is correct for your ims.
I'm a little confused. Does this mean my crank is the wrong type? When we initially pulled the engine it looked like it had never been opened or separated from the transmission. Apparently the crank I have works sonce now everything seams to be moving forward smoothly with the rebuild kit I bought and the heads redone. I had the heads redone by a Formula 1 engine mechanic. Still puzzles me how my car has this engine. The car looks in excellent shape and well taken care off. Who knows what the previous owners did. The service records I have never mention the IMS being done or any engine rebuild.
Rennlist Member
Joined: Sep 2016
Posts: 87
Likes: 2
I am hoping for some advice; frequent reader of these but first question.
when i bought my 2002 996 c4 cab 3+ years ago with 44k miles(now 68kmiles), my research indicated that the 3.6l engine had lower failure than the earlier 3.4, this doesnt seem to be the case. fortunately the car is still going strong. i have replaced a number of parts(exhaust, brakes, top mounts, etc) but the RMS has gone and about to get it replaced, and the clutch.
I asked for a quote from my indy that has done the recent work, and i noticed the ims upgrade bearing was missing, it just had a new IMS cover + installed. So i phoned and asked if there was a mistake and the answer was we dont do the IMS mod. we leave it alone. So i pushed a bit more, and they said they just dont do it and they suggest keeping it original.
So question is, do i need a new Indy that will do it, or is the IMS replacement just not done to most cars?
when i bought my 2002 996 c4 cab 3+ years ago with 44k miles(now 68kmiles), my research indicated that the 3.6l engine had lower failure than the earlier 3.4, this doesnt seem to be the case. fortunately the car is still going strong. i have replaced a number of parts(exhaust, brakes, top mounts, etc) but the RMS has gone and about to get it replaced, and the clutch.
I asked for a quote from my indy that has done the recent work, and i noticed the ims upgrade bearing was missing, it just had a new IMS cover + installed. So i phoned and asked if there was a mistake and the answer was we dont do the IMS mod. we leave it alone. So i pushed a bit more, and they said they just dont do it and they suggest keeping it original.
So question is, do i need a new Indy that will do it, or is the IMS replacement just not done to most cars?
Nordschleife Master
Joined: Sep 2006
Posts: 7,913
Likes: 25
The small single row bearing found in the original 3.6l motors indeed has a higher failure rate than the older dual row that was found in the early 3.4l motors, but it's still not a certainty by any stretch. There are a couple of 200k+ mile cars running around this forum on their original single row bearing.
Unfortunately the IMSB also gets the blame for failures when it was just a victim (people just see metal in the oil or pull the transmission and find a trashed bearing and blame it as the source without looking further).
If it were me and I had a single row (I thought I did, but turned out to be a dual), then I would have had it done with the clutch. You're in there, so you might as well is my view. Now that your's has been buttoned back up, it becomes trickier as you have to pay for the same labor all over again (removing the transmission).
If you are worried about it though, get it done to take it off your mind. The extra labor is worth the lack of stress.
I would say, however, that if you get it done, find another shop. Your guy seems adverse to doing it which suggests that has doesn't have much experience (maybe with the m96 at all?). As I understand it the job isn't difficult, but it is easy to screw up and make a royal mess. He also isn't likely to go through the process of LNE's pre-qual and that process has more to do with what happens to your motor than the bearing change itself.
At this point I don't know if I would stress over the bearing or not in your shoes, but I'd definitely start looking for a new Indy that is more familiar with the M96.
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
9 Features and Characteristics That Only Porsche People Understand
Verdad Gallardo
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way
Joe Kucinski
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)
Verdad Gallardo
Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner
Joe Kucinski
This Builder Is Turning Heads With Its Slantnose 911 Creation
Verdad Gallardo
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture
Verdad Gallardo
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look
Verdad Gallardo
10 Porsche Colors That Have More Personality Than Most People
Verdad Gallardo
Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod
Verdad Gallardo
Rennlist Member
Joined: Mar 2006
Posts: 6,570
Likes: 89
From: Austin
I'd lean towards getting the IMS bearing replaced as PM. Labor for RMS and clutch should be the same as for RMS, clutch and IMSB.
6th Gear
Joined: Jan 2016
Posts: 6
Likes: 0
From: Missouri
IMS
I am guessing that your Indy hasn't ever replaced one and does not want to buy the proper tools to do it with. LN website offers 8 or 10 certified installers all over the country. One should be near you.
Three Wheelin'
Joined: Apr 2016
Posts: 1,946
Likes: 23
Race Director
Joined: Sep 2012
Posts: 10,424
Likes: 229
From: SOcialist republic of CALifornia
Three Wheelin'
Joined: Apr 2016
Posts: 1,946
Likes: 23
haha, touche
funny thing is my IMSS did require 2 weekends in Central CO. Upon returning to SLC I noticed a shop 4 miles from my house was added as a certified shop. Kinda funny. I love Colorado though, we drove the 996 through the CO national monument, visited a distillery, vineyards, etc. Not to mention monstering through the desert with a singing m96 behind us!
funny thing is my IMSS did require 2 weekends in Central CO. Upon returning to SLC I noticed a shop 4 miles from my house was added as a certified shop. Kinda funny. I love Colorado though, we drove the 996 through the CO national monument, visited a distillery, vineyards, etc. Not to mention monstering through the desert with a singing m96 behind us!