kbollaert

IMS bearing in my 99 was fine. The IMS itself spun the gear, wrecking the valves, pistons, etc. though.
Rebuilt, with the IMS pinned @ LNE.

suprmedic

OK, so I went ahead and took my C4S into Precision Motion today to get the IMS, AOS, RMS and clutch done. Figured I would do it now so that I would not have to worry about anything for a while. Really just looking at it as insurance. The people at Precision are all involved with PCA.org Riverside area and seemed like good people. Garage full of Porsches.... old and new. Cool stuff.

ZX9RCAM

What kind of quote did you get?

suprmedic

$2875. I'm glad that I found a Porsche shop with a good rep reasonably close to home.

ZX9RCAM

Sounds lucky to me....

NIACAL4NIA

Replaced a slipping clutch and LN ims bearing at 90000 miles. The original ims bearing looked good as new. I'll post a photo.

TempleCloud

I've been told by a reputable and large Porsche specialist garage in the UK that much of the IMS bearing panic has been created by those selling kits to replace the standard bearing and making lots of cash through the unecessary panic.
The fact is, so they tell me (and if I'm getting it right), the the real issue is the size of the bearing (you need a larger one) not the metal used or the number of bearing runs.
I've also been told by another company that there are a number of unscrupulous garages charging for the (often unecessary) work and not even changing the bearing itself.
So think very seriously about your own situation before rushing into doing anything to your 996. And don't talk to those who flog the kits but either a Porsche main dealer or reputable specialist who doesn't depend on this type of work to exist
I've just bought my second and was looking into the whole IMS thing when I spoke to this specialist and who gave me his insights.

TempleCloud

that should be

Flat6 Innovations

Anyone who has experienced an IMS Bearing failure will disagree with this. Their experiences will be fact, not fiction, or opinion.

Let's not first that here in the US the issue was substantial enough to lead to a Class Action Lawsuit where Porsche admitted to an 8% IMSB failure rate in the single row equipped cars. Thats the percentage that was "agreed" upon when the settlement was initiated.

Believe what you want. Hopefully you'll always be listening to the opinions of others, rather than telling others your story from a first hand perspective.

We don't depend upon the sales of any IMSB Retrofit kit to survive. In fact, we benefit when people fail to address the problem preventatively, either because they don't know the issue exists, or because they fail to believe that it can happen to them. What drives our business is failures of engines, and people wanting to carry out elective reconstructions to get more power, and a more robust engine.

Everyone has some opinion, let them answer my phones for a week here, and I'll bet that their outlook would be different.

TempleCloud

I'm not quite certain what you're saying but I'm sure you'd agree that its important for those with 996s that are concerned, to seek advice from either Porsche main garages or reputable Porsche specialists that don't depend on this type of work to exist.

Flat6 Innovations

You may not be sure about what I am saying; but, I am very sure that I understand exactly what you are saying... That we have fabricated all these stories and issues.

I challenge you to find one single thread that has been started on a forum from my company, or LN Engineering about this topic. I challenge you to find one single article that we have published about this. You won't find one. You will find some articles where we have been interviewed, but these were occurrences where we were asked by a publication for input.

Absolutely not. Why would you ask someone a question about this who does not see the failures? The only reason you would, is IF you were looking for Unicorns or Rainbows, wanting not to believe the issue occurs.

Further, if a Porsche specific shop has not seen IMSB failures, you don't want them to work on the car anyway, because they obviously lack first hand experience. These are the people who mis- diagnose the failures, and waste the owner's money. You want someone who has been there, and done tat, and learned the hard way before your car ever finds it's way into their shop.

That said, my company has been in the engine building and development business since the days that the 911 was aircooled. We NEVER have depended upon any water cooled Porsche engine to stay in business, and we have never depended upon the 996 "to exist".

I just finished installing an engine into a 600 thousand dollar Speedster, I have a 964 based (4.1L) engine on my bench, a 993 based (4.1) engine in machining, I just finished a 930 engine, and a 4.8L Cayenne Turbo and have two 996 Turbos apart being built into a 3.8 and a 4.0L. Thats just whats apart and has just been finished, it doesn't include any of the backlog for the next 13 months.

If we never sold another 996 engine we'd keep right on trucking along. I wouldn't be able to be quite as selective with the other work that I accept, but the bank account would look the same.

Keep in mind, aircooled Porsches paid for 100% of the development of the M96/ M97 engines that we have to offer today.

What I will say is important is to use ALL the resources available to you before you make any decisions about what to do. This includes articles, forums, and local shops (not just one).

Remember, the posts on these forums prior to 2007, when we developed the IMS Retrofit procedure used to be "My IMS Bearing is failing, shops says I need a new engine". Thats right, times have changed, but the one thing that has always stayed the same has been the critics that are never happy with the fact that some dedicated, hard chargers worked their asses off for years to offer every owner the option of retrofitting the IMS Bearing.

At least you have an option, but its easier to criticize, and blame. Isn't it?

islaTurbine

Well said.

TempleCloud

Your paranoia is overwhelming......and telling.
But I'll leave it there as you quite misunderstand me.
Have fun....

jmj951

Other than the statement about carefully selecting a shop to maintain your car, the rest is extremely poor advice. A ball bearing is not a permanent, lifetime solution for anything. It has moving parts, and it wears. Many of these IMS bearings fail, and the result is catastrophic.

I have no shop and I don't sell anything, I'm just another owner who has the (more reliable) double-row bearing almost come completely apart at 75k miles, and had to have it replaced. I was lucky that I still have my engine. This problem is very real.

The engine shop I used (top tier experience with both race cars and daily drivers, all years) also highly recommends the larger stock bearing be retrofitted to 996's by using the 997 IMS shaft and stock bearing, with the bearing seal removed. It's not an option for all 996's though, because the chain sprockets are different on the very early 996's. An early 996 crankshaft sprocket will not be compatible with the later 997 intermediate shaft. However, the large 997 bearing is not a guaranteed, foolproof solution either. You'll also hear that some of the larger 997 IMS bearings have failed too (don't know if those bearings had a grease seal, or had it removed as recommended by numerous Porsche specialists). The shop I used removes the IMS bearing grease seal on every 996/997 engine they work on (even cars that are just in the shop for a clutch and new seals), and they have never had one come back with an IMS bearing failure.

TempleCloud

That was , in fact, the ONLY advice I gave.

I'm glad that you seemed to confirm one point of mine however - that it's the size of bearing that's more important than the number of bearing runs.

One thing owners need to look at is the value of getting their bearing changed relative to the cost of failure.

Say the odds of failure are around 12/1 and the cost is, say, £8-10,000 (?) and, in the UK at least, the cost of changing to a new bearing is £3-5,000. Is there value in changing the bearing without a reason ? On the face of it, no. Not if you're a good gambler at any rate.
However, what the odds don't reveal are the relative odds of failure compared to mileage done. It would be interesting to see that breakdown if anyone has the data.