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Hi Jake,
Noticed your concern of the asymmetric wear on the inner race and how it may indicate a problem.
I had my bearing (double row) changed out a couple of years ago (LN) and didn't return the old bearing. Apologies to me. But I just dug up the old inner race and it definitely is worn only on one side. Seems to make sense since this race is stationary, wouldn't it only fail on the loaded side and not indicate a machining problem? It is connected by a chain w/ tensioner, so I wouldn't think chain bind would be an issue. If the IMS can be off-axis and/or the bearing itself can be off-axis when pressed in far enough to be a problem (everything is off-axis), I can only shake my head. Seems to be the case here. (If so, a roller bearing wouldn't seem to help very much.)
I have a careful watch on my oil and am a bit concerned since there is always a bit of residual glitter in the filter from the 1st failure despite having changed the oil 10 times in 20K miles and cleaned the pan. If there is another mode of failure besides just losing the grease in the OEM bearing, then I might need to think about a more radical approach to PM if the IMS Retrofit can have issues. Or it's rebuild time. Engine is still strong and smooth, so knocking on wood.
If the bearing is properly loaded and aligned, the entire race will carry the load, not just one area.
Point loading is the big issue with misalignment and that's what creates the localized wear that you've noted.
I have seen the inner race wear at all sorts of various points over the years, and it's not always in the region where it's expected. There have been times where the wear was concentrated 90 degrees from the area that should be the most heavily loaded.
Dual row bearings also wear much differently than single row and we seldom ever see localized race wear like you speak of since there are two surfaces carrying the loads, not just one.
If you had a dual row with localized wear, I'd be concerned with alignment issues.
Thx Jake,
Many things are NOT intuitive, so I accept your views on this since you've seen so many
engines and their issues. I'll have to be the eternal optimist and keep watching the oil,
the old "causality vs. correlation" rationalization. If the few flakes trend starts upticking, then
I will have figure out what to do, not driving being one of the immediate actions.
For entertainment purposes, here's a pic of the double row showing the localized failure.
This thread looks to be over one year since last post, but I recently had a LN ceramic single row p/n 100124200 fail on my 2005 997 @~30Kmi. Orig OEM was proactively replaced @40Kmi, showed no ware.
Jake, are you interested in further details?
This thread looks to be over one year since last post, but I recently had a LN ceramic single row p/n 100124200 fail on my 2005 997 @~30Kmi. Orig OEM was proactively replaced @40Kmi, showed no ware.
Jake, are you interested in further details?
Yes, but your first step is to contact LN with the details. That's the first step anytime you have a problem with any component.
If you truly want to find out why this occurred, it's important not to start disassembly and etc. There's a considerable amount of measurements that need to be made.
Thanks Jake for your timely response. Who should I ask to speak to at LN?
Engine at shop already disassembled. Previous owner had LN bearing and RMS installed, I have shop paperwork with date and mileage. What measurements can I have my current shop (LN preferred) make to check bore alignment? My thinking is bore OK based on 43k orig miles with no reported problems on orig OEM bearing. LN install was reported performed as proactive move. Inspection upon engine removal at 70Kmi showed no oil leaks around RMS or LN IMSB. Also of note, magnetic drain plug and spin on filter was installed, DT40 5W-40 oil changes @5Kmi was routine.
Thanks Jake for your timely response. Who should I ask to speak to at LN?
Engine at shop already disassembled. Previous owner had LN bearing and RMS installed, I have shop paperwork with date and mileage. What measurements can I have my current shop (LN preferred) make to check bore alignment? My thinking is bore OK based on 43k orig miles with no reported problems on orig OEM bearing. LN install was reported performed as proactive move. Inspection upon engine removal at 70Kmi showed no oil leaks around RMS or LN IMSB. Also of note, magnetic drain plug and spin on filter was installed, DT40 5W-40 oil changes @5Kmi was routine.
I can't speak for LN, I tend to only deal with technical issues.
With the engine disassembled you no longer have a perfect case to study. The measurements that need to be taken require the engine to be assembled, to be gathered correctly. This requires special tooling that I developed, but has yet to be mass produced and sold. Some of the dimensions can be taken with the engine partially assembled, and others with the engine apart completely.
That said, the first phone call to LN (or any manufacturer/ supplier) should occur before anything is disassembled, and even before posting things to forums. If this doesn't happen the supplier cannot do their part, and often times nothing is learned from the instance.
In that case you can suffer another failure later on from something that's not found during the repair.
What I'm stating is just general information as I can't speak for LN. I know if I ever have a customer with my engine that has a problem, that I need to be the first person to know about it.
I might have missed this in your read, but LN has the Single Row Pro IMS also which is an updated design with a dual row of ceramic bearings.
Just had this done in my 11k mile C4s. Hope is last. I think your failure is an rarity. Ln has stated an zero failure rate. Yours maybe the first.
I might have missed this in your read, but LN has the Single Row Pro IMS also which is an updated design with a dual row of ceramic bearings.
Just had this done in my 11k mile C4s. Hope is last. I think your failure is an rarity. Ln has stated an zero failure rate. Yours maybe the first.
From what I gather the poster has the Classic Single Row, not the Single Row Pro (dual row bearing which fits the single row application).
To date there's been no failures of the Single Row Pro, or IMS Solution.
I can't speak for LN, I tend to only deal with technical issues.
With the engine disassembled you no longer have a perfect case to study. The measurements that need to be taken require the engine to be assembled, to be gathered correctly. This requires special tooling that I developed, but has yet to be mass produced and sold. Some of the dimensions can be taken with the engine partially assembled, and others with the engine apart completely.
That said, the first phone call to LN (or any manufacturer/ supplier) should occur before anything is disassembled, and even before posting things to forums. If this doesn't happen the supplier cannot do their part, and often times nothing is learned from the instance.
In that case you can suffer another failure later on from something that's not found during the repair.
What I'm stating is just general information as I can't speak for LN. I know if I ever have a customer with my engine that has a problem, that I need to be the first person to know about it.
Understand your guidance Jake. However, in my situation, knowing the LN single row ceramic was installed, the bearing was assumed to not be the source of engine problem. Assumption was timing chain or tensioner breakage. This is why call to LN was not made first. Only upon dissambly and discovery that LN ceramic had failed have I now started reaching out. I will call LN in morning, but would appreciate a contact in their engineering department vs. customer service if you can offer that up.
From a technical perspective, as far as measurements of bore alignment, can you offer what crank shaft and IMS bore centerline should be referenced to a datum? Tooling aside, this should be the fundamental data set. I presume you have measured numerous blocks and perhaps you could share your findings with the community?
Also from your technical experience, has there been history of LN ceramic bearing failing at <30K? I am more than willing to share pictures and my parts with you if you think it useful to analyze.
Thanks in advance for your feedback.
As a matter of procedure, always contacting the manufacturer before going to the forums is good practice when you are going to be asking for help from the manufacturer, especially when there is no warranty.
The M96 engine has more than one mode of failure - it's always easier to blame the IMS bearing, especially if it's been retrofitted. What I will say is if we find a defective single row bearing, it will go almost immediately (say within the first month/1,000 miles), not years or tens of thousands of miles later. More than likely the IMS bearing is a casualty of the other failure - with an open bearing, any FOD (foreign object debris) can result in catastrophic bearing failure.
Please contact LN by email or phone - we will need the serial number of the bearing (to look up the registration) and any supporting documentation from the original installation for review to verify proper pre-qualification. I will look into this further personally.
Understand your guidance Jake. However, in my situation, knowing the LN single row ceramic was installed, the bearing was assumed to not be the source of engine problem. Assumption was timing chain or tensioner breakage.
When Instructing my M96 Engine Classes we focus on systematic diagnosis. When this is carried out, the root of the issue is exposed much more quickly, and the engine can be diagnosed without disassembly in 90% of cases. As an example, at the first sign of any timing issue, the engine should be rotated to TDC, then the green camshaft tunnel end plugs should be removed. If the camshafts are out of time on both sides of the engine then some issue with the intermediate shaft has occurred, and is creating a global problem for both sides of the engine, equally. If the issue is only creating a cam timing issue on one bank of the engine, then you have an issue limited to the one side. The next logical choice is then to pull the IMS Bearing flange, since it's next in line from a camshaft drive perspective, and everything is guilty until proven innocent. It does;t matter who made something, or how new it is, the process must not be altered.
A shop that is adequately proficient with the M96 engine should get to this point within 1 hour of the diagnosis process. If they don't, there's only two reasons:
1- They do not know this specific engine well enough.
2- They want to take it apart to get a commitment from you, so you can't easily take the car/ engine elsewhere.
I see the latter play out all the time these days. Lots of the people taking these engines apart don't know what kills them. Jumping in head over heels with a haphazard, full engine disassembly of the entire engine is not wise. There's no reason why this engine should have been taken completely apart, knowing that it had a suspected camshaft/ intermediate drive issue, be it a timing chain, or otherwise.
I pluck cars off the lots of shops all across the country, all the time. This usually occurs after instances similar to this where someone pulled something apart. I see cars all the time with the entire engine disassembled and jammed into the trunk, and interior of the car. We call that a "trunk job".
This is why call to LN was not made first. Only upon dissambly and discovery that LN ceramic had failed have I now started reaching out.
Why was't this noted prior to complete disassembly? That would be my question. To lock the crankshaft at TDC and remove the IMSB flange takes a total of 5 minutes to do. Also, before splitting case halves this flange also must be removed. Even if no one caught the issue before reaching that point, there's no reason why they went further than that, once they saw the condition.It does;t add up from my perspective.
I will call LN in morning, but would appreciate a contact in their engineering department vs. customer service if you can offer that up.
Charles replied to that portion of your statement. Never under estimate Charles, I have seen him do some amazing things for people who keep calm, and respect him. We've been working together for 17 years, and during that time I've also seen him deal with some jerks, too. I know from experience that he believes in the Golden Rule. He's a much nicer guy than I am, thats for sure!
From a technical perspective, as far as measurements of bore alignment, can you offer what crankshaft and IMS bore centerline should be referenced to a datum? Tooling aside, this should be the fundamental data set. I presume you have measured numerous blocks and perhaps you could share your findings with the community?
This is my proprietary information. I have learned not to share values like this publicly, especially when they are even loosely associated with a tool Patent that I have pending. Further, without this tool the values cannot be gathered in any other way due to variations in crankshaft carrier down positions that can shift the crank carrier in the crankcase, in regard to RMS bore diameter. You must worry about the crankshaft centerline aligning with the RMS bore, as well as how both of these effect the distances to the centerline of the IMS.
What can be done is setting up the IMS shaft assembly in a set of V blocks, and measuring the values to the root of the sprockets, and the shaft on all surfaces. To do this you just need to gather all of your own data from 4 different axes of the shaft assembly, on all 3 drive sprockets. Compare these to the centerline of the housing bore inner diameter where the IMS Bearing resides.
As an example of how wildly mis- manufactured some IMS shafts can be, see the results of this study back in 2014 that have been shared to dropbox, for use in my classes. We've seen some shafts that were even worse than this! This explains why some engines have had multiple IMS bearing failures after being repaired, and even some times after engine have been "rebuilt" (not by us!) IMS Shaft Study
Also from your technical experience, has there been history of LN ceramic bearing failing at <30K? I am more than willing to share pictures and my parts with you if you think it useful to analyze.
Thanks in advance for your feedback.
No.
That said, keep in mind that at my facility we have carried out almost 600 IMS Retrofit procedures, including the very first one. Of those the majority have been with the IMS Solution, since its the only product I have used since 2011, and I tend to go overkill with everything that we do. Not only that, but its my Invention, and there's a reason why I spent over a decade perfecting it.
Of those 600, around 180 of them have been carried out with the exact same product that you have experienced disappointment with. This is more than any other company in the World, by hundreds of percent. The last of them was in 2011, some 5 years ago. Of those 180 units we have had ZERO failures to date. If the Classic single row had issues that were not related to collateral damages, then by the law of averages, we would have seen not only a failure, but more failures than anyone else- this hasn't been the case. The same goes for Callas Rennsport, the #2 installer in the USA, who has also not had a single failure. This proves that a proper procedure, coupled to not retrofitting every car that comes in the door is the key to success with this procedure.
Both of our companies share the same attention to detail, and carry out similar exhaustive pre- evaluations before engines are retrofitted. We don't treat the job like a brake job, just throwing some parts at it, and sending the car down the road. In general a shop does;t care, as its not their product, AND if it fails, well, they just stand to make even MORE money from their customer (yes, I have had a shop owner in my class say that out loud). If an engine fails even one aspect of this evaluation, it is not retrofitted. Doing this gives the best chance of success; because, remember, everything is guilty until proven innocent.
A good example of an issue like this is a car that came to my facility for a full reconstruction a couple of months ago. The owner stated that he heard a growling sound from the engine, so he parked it (smart man, he didn't drive it to death). When I disassembled the engine, one of the first things that I did was quantify valve timing, which was about 4 degrees over advanced, and equally on both sides of the engine. Knowing that the ONLY way that cams can see additional advance is by having the IMS drive chain bee too taut, my very next move was to remove the IMS chain tensioner. When I removed it, I found that it has basically exploded, and then had jammed int a hyper extended position, where it was about 3/8" longer than it was supposed to be, and it was no longer functioning hydraulically. I found this before the engine was even removed from the car!
After contacting the owner to tell him about this, and gaining permission to go more invasive with diagnosis (in writing) we pulled the engine and pulled it apart. I knew this had to be done; because the failure HAD already broken the IMS tensioner paddle, and the only way to address this was to pull the entire engine apart to facilitate repair.
When I pulled it apart, guess what? The IMS Bearing was also failing, but only from collateral damage related to the chain tensioner failure.
So, as you can see, forensic mechanicology must be exercised, along with exceptional judgment, if one intends to gather the full story from any failure associated with the M96 engine.
Jake ,
Thank you for taking the time to give these anecdotes. I have read many of these threads and benefited from doing so. I acknowledge that th time you spend writing these Posts is time you probably should be spending on work you already have piling up in your workshop.
The anecdotes about chain tensioners and paddles are the most useful part of your Posts for me because they give a specific example and cause for a Mode of Failure that is otherwise classified as "IMSB damaged by FOD" .
The specifics of the tensioner failure also make clear how 'sensitive' the M86 is. Having a tensioner over-extend by 3/8"(9.5mm) does not seem lke much until you read what the damage costs to repair.
In this specific case, if an inexperienced person dismantled this specific engine, I doubt they would have noticed or understood the significance of they did.
So is this a new number in the "Mode of Failure" list ?
Thank you for explaining to us.
05-12-2015, 08:58 PM
Here's to hoping it stays that way.
