Replace a double row IMS at clutch time?
 

Trying to decide whether to replace the IMS. No question I'd do it on a single row. But with a failure rate of <1% on the double row bearing, 80k motor, and no sign of shavings in the oil filter (we cut it open to inspect)...... replace the IMS with the $800 LN bearing? Or even a single row Pelican parts bearing for $150?

Do it. And with a double row. What is the downside? I can't think of any. You'll have piece of mind, relative low cost, higher resale value, higher warranty 7/70.

Nope. No logical reason to mess with it.

If it ain't broke, don't break it by trying to fix it.

How are the Durametric cam timing deviation readings?

I'd definitely replace the RMS while you're doing the clutch. IMS...do you plan on keeping the car a long while? Would you like to have total peace of mind? Is that worth another $1000 to you?

I did it on my '02 S when we pulled the trans to replace the leaky RMS. At 68k, my single row bearing had no signs of failure (shaft didn't have any play at all), but the seals were definitely blown.

I'm quite pleased to be able to use the car as it's intended and not think twice about it now.

Not the single row, that makes no sense to me. Why inject the risk of intervention only to get the same materials but less capability of the single row you mentioned.

The 1% was 5 years ago. Age and mileage have increased since then. All rotating parts wear.

I think I'd consider the expertise of the mechanic doing the work as one of the factors helping me make the decision. Right tools, right instructions, any vendor training, experience with the tools and specific bearing I was choosing?

If I was paying for the labor or doing it, the increased parts cost would be a trivial item. Do it once and do it right.

Having said that, I can't tell you the number of cars I've sold that the buyer got 80%+ of the benefit of my investment. Consider how long you think you'll keep the car.

And what else should you do while the transmission is off the engine? The AOS change is a classic choice.

It is easy to spend your money.

As the proverb goes.....
 

....if it can't hurt, but might help, do it.

:cheers:

Here is a different approach to consider.
One early sign of IMSB failure is oil inside the 'sealed' IMSB. By the time there is metal in the filter it may be way too late .
So remove the cover, pry off the bearing seal and inspect for oil ? Test bearing for wobble.
Many of the new kits have this front seal removed to improve the lubrication of the bearing so this does no harm.
If you find no grease and just oil in the bearing, ask for more opinions?
Remember the replacement kits also upgrade the weak grooved bolt.

Great discussion. I had always figured I would do it when I replaced the clutch.... but this thread brings up some good points. Subscribed.....

Yeah, good point. I hadn't thought about the resale value. Thanks.

Yes, doing the AOS and RMS with the clutch.

Don't overlook the simple precaution of connecting Durametric and checking for Codes and excessive Deviation. Now is the time.....
Even simple things like replacing "O" rings on the Heat Exchanger are easier to access with the transmission out of the way.
Yes it is easy to spend the money but you'll spend way more if you don't do it now. Unless of course you are just flipping the car.I hope not ?

Yes! Replace it while you are in there. I had 87K on my 99 and found metal in the oil filter. Did clutch, flywheel, RMS and IMSB. The IMS was full of metal shavings. Bearing was worn but intact. Cleaned it out as best as possible and install new bearing.

And, no, not all engines are doomed if you find metal in the oil filter. Has there been some damage to bearing surfaces, probably yes. Will my engine last forever, No. But it has already surpassed my expectations and seems to be going strong.

Today I rolled past 19K miles since fixing the IMSB.

PS: I do change and change/inspect my filter every 3K and change the oil every 5 to 6K. Next oil change I will drop the pan again for the second time since fixing the bearing.

The problem with this is that, at least in my case, the shop had to order the LN Engineering replacement bearing ahead of install.

If you go with a different IMS upgrade, that might not be an issue.

I needed a clutch in my 2001 S at 45,000 miles and planned to do the IMS bearing because of the model year uncertainty of single (high failure rate) or dual row bearing. When my mechanic got the car apart, we discovered a dual row bearing. Replaced it and found the original bearing was fine. I felt better since I plan to keep the car for a while. It has 68,000 miles now without a hiccup.

Ask your question from a different point of view...why do you buy insurance? Simple answer, the odds of a accident are low, but the costs of an accident can be high.

The IMSB question is similar as is the answer...the odds of a failure are low but the costs of a failure are high.

Replacing the IMSB is cheapest when you're replacing the clutch.

Have you ever done a Blackstone lab oil analysis. It will find metal in the oil you can't even see. I did one on my 75k dual roll bearing '88 and the report said there was less metal than expected (compared to the average car...not Boxster.) That told me I didn't have to worry about it for a while.

Blackstone Labs

Good news bad news
 

Went ahead with the LN IMS Pro. Turned out that despite the VIN number indicating otherwise, the motor had the single row bearing in it anyway. Bad news, wound up needing a flywheel. The flywheel was about $500 and the clutch kit was $650. Hoses, fork, RMS added a few hundred more. Is 10 hours labor about right?

My whole job too 11 but they also did a brake and clutch fluid change that added an hour. 10 hours seems right.