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I purchased my 4S about 6 months ago, and like many of you have the IMS crosses my mind pretty frequently. The car had the IMS replaced 12/13 @ 78k with a single row IMS retrofit kit. Part number on the receipt reads the same as this: http://www.new-part.com/product/engi...er-996-carrera
So now, my car is @ 101k. I believe LN rates this part's wear life at 4 years or 50k. The part only has about half that mileage but we just crossed 4 years since installed in my car. Is there any data on failure rates for LN Retrofit bearings? Does it make sense in my situation to open it up again and replace? If I did so, I'd most likely bite the bullet and go for the solution. Am I overthinking this?
I read the OEM IMS failure rate is cited to be around 8%, is there any data showing the LN Retrofit failure rate? Trying to weigh the risk/benefit ratio on this one. Another point to consider is the clutch was just replaced on the car in the last year so unfortunately I can't kill two birds and knock out the IMS "while I'm in there".
I’m in the exact same situation, ironically with a C4S, too. I bought it in December. I called LN, & the person I spoke with was suprisingly forthright. I expected the recital of the 4/50 service life recommendation, but he told me that they have had maybe 5 of the “classic” retrofits fail, all in engines that had debris from either a partial IMSB failure or something else (I’m paraphrasing here). He didn’t say “don’t worry about it,” but he sure gave that impression. You may want to give them a call next week to see if you get the same feeling I did.
I’m under the impression that the materials & available lubrication are far superior to a stock bearing that had the seal compromised. Certainly the “pro” retrofit or the solution are better options, but the classic should be better than the stock one that had a 92% (not sure how relevant the 8% failure figure really is) success rate.
I wish you the best of luck with your decision. When I need a new clutch, I’ll certainly replace the IMSB, & I hope that it’s not needed before then!
IMHO you're good to go for a couple of more years. 4 yrs /50,000 mi. is the very safe interval, probably conservative to the extreme. Thousands of these same bearings have been in cars for 14+ years, 100K+ miles. And when those "old" ones are pulled by owners we've seen them come out in excellent condition and didn't need replacement. If you can't sleep at night, replace it. I wouldn't touch it, but it's your car, your money, and your peace of mind.
Bottom line, your car had a lifetime part replaced with a wear item that LN recommends replacement Therof at the stated intervals. You have three options:
1. Replace the part per the service interval recommendations of LN.
2. Replace that part with a lifetime part (the LN solution).
3. Roll the dice and see what happens.
Bottom line, your car had a lifetime part replaced with a wear item that LN recommends replacement Therof at the stated intervals. You have three options:
1. Replace the part per the service interval recommendations of LN.
2. Replace that part with a lifetime part (the LN solution).
3. Roll the dice and see what happens.
If you do choose to replace it, there is a mail in rebate on upgrading to the solution.
Re: failures. I'm open and honest about this and have said so publicly on the forums for years. It's all part of the public record. Any part supplier that says they don't have failures is straight up lying. Like with any mechanical system, things wear, and will eventually fail, it's just a matter of what and when. Same goes with the IMS bearing - how the car is serviced, what oil is used, and how it's driven, among a million other things will affect the projected lifespan for any one component. There are thousands of kits that have been in service now over 10 years without problems.
We just had a report of a failure of a classic single row IMS Retrofit that was in service past the 4 yr mark, but thankfully, the owner of the car had a spin on oil filter adapter and he changed his oil every 3k miles and cut the filter open and also regularly dropped the sump. His being proactive let him find the bearing in a very early stage of failure and the filter caught 100% of the debris. He's putting in a Single Row Pro and he'll be good until later in the future when he plans to do an elective rebuild and upgrade his engine and will go with a Solution at that point.
It's a shame when Porsche released their retrofit kit with a single row ceramic hybrid bearing (just like our classic single row ims retrofit) that they didn't release a TSB or directive with how to install, what tools to use, or how often to change it.
That said, of actual installs where the car was properly pre-qualified, following our directives, it's true that the failure count is probably no more than 5, where the bearing truly was defective. We have others fail over the years where corners were cut or bearings were fitted to engines that clearly should have never been retrofitted. I've seen everything from bearings cut out to work orders requesting used oil to be drained and re-used after the new bearing is installed without pans being removed to inspect the sump for debris.
Re: failures. I'm open and honest about this and have said so publicly on the forums for years. It's all part of the public record. Any part supplier that says they don't have failures is straight up lying. Like with any mechanical system, things wear, and will eventually fail, it's just a matter of what and when. Same goes with the IMS bearing - how the car is serviced, what oil is used, and how it's driven, among a million other things will affect the projected lifespan for any one component. There are thousands of kits that have been in service now over 10 years without problems.
Hi Charles, are you saying that it's your experience that there are Retrofit Kits that have been in service for 10+ years, or are you referring to the Solution?
I read the OEM IMS failure rate is cited to be around 8%, is there any data showing the LN Retrofit failure rate? Trying to weigh the risk/benefit ratio on this one. Another point to consider is the clutch was just replaced on the car in the last year so unfortunately I can't kill two birds and knock out the IMS "while I'm in there".
plenty of scare stories around especially from mechanics desperate for business. However I can't find any evidence to say a retro fit by anyone will last longer than original.
There are people on this site who have had other supposedly better retro IMSB fail.
If it ain't broke don't fix it
Hi Charles, are you saying that it's your experience that there are Retrofit Kits that have been in service for 10+ years, or are you referring to the Solution?
There have been zero failures of the Single Row Pro or Classic Dual Row Retrofit kits. Likewise, the IMS Solution also has a flawless record. That said, there are Classic Single Row bearings that have been in service now 10 years, well past the recommended service interval. As with any mechanical part, the longer it is in service, the greater the likelihood that it will wear out or fail. There is a reason why manufacturers recommend timing belts on those engines where it is not a permanent chain - some at 60k, some at 100k. The idea is you change it before it fails.
There have been zero failures of the Single Row Pro or Classic Dual Row Retrofit kits. Likewise, the IMS Solution also has a flawless record. That said, there are Classic Single Row bearings that have been in service now 10 years, well past the recommended service interval. As with any mechanical part, the longer it is in service, the greater the likelihood that it will wear out or fail. There is a reason why manufacturers recommend timing belts on those engines where it is not a permanent chain - some at 60k, some at 100k. The idea is you change it before it fails.
don't forget for you to known something has 0 failures you would have to know every one that was fitted and be in touch with everyone that has one fitted, sounds like a broad claim.
I'm not doubting your product but do you know every car that has one.
Considering the expectations of customers that spend the several thousand dollars it takes to preemptively replace a part that has an 8% failure rate, I suspect that LN Engineering would hear about any failures.
To your point, maybe they should claim they’re not aware of any failures instead of stating they’ve had no failures.
Considering the expectations of customers that spend the several thousand dollars it takes to preemptively replace a part that has an 8% failure rate, I suspect that LN Engineering would hear about any failures.
To your point, maybe they should claim they’re not aware of any failures instead of stating they’ve had no failures.
and don't forget 8% over the life of a car, so 15 year old car
0.5% per annum, so 1 in 200 per year most people keep these cars for around 3 yeas so 1.5% chance on average while you own the car,
changing it does not make sense unless it's gone
"Gone" as in bearing is gone? If that's what you mean, it's too late - you'll be looking at an engine replacement.
Is that a fact or your opinion,
Worst case and unlikely an engine rebuild, best case just a bearing.
and for every 100 bearings changed probably 3 needed it(excluding broken ones).
These garages are no better than scaremongering robbers, claiming their products have never failed,
and banging on, ohh! if you don't change it, it will fail, BULL!
I've had 996+997's and absolutely hammer them to the redline and beyond,
never a failure.
02-23-2018, 07:19 PM
Another IMS question (Replace LN Retrofit?)
