My IMSB - Story & Pic's
 

Hey Guys - Lots of threads on IMSB failures and solutions lately so I thought that I would add mine to the mix and ask a couple of questions.

The history on my car:

2000 Boxster S w/29K miles.

I'm the second owner, and have had the car for about 6 months now.
Private party sale to me. Previous owner had all service records. Since purchasing the car, I have performed just about all aspects of the 30K service.

I'll be attending my first PCA DE later this month, so the condition of my ISMB was looming in the back of my mind. With every high rev, I would always wonder...could she blow? Yes. Is she going to blow? I don't know.

The original owner special ordered this car when it first was announced as a second car and then traveled all the time on business, so the car basically sat. We all know the story... The oil was changed, but only once a year at the dealership.

I live in Austin, TX - so winters are mild...

So I decided to have the work done. LNE ceramic. Thanks to the many people that post on this forum, I had precluded that my car had a dual row bearing. Sure enough, it did and I was happy to see that.

My bearing was extracted and looked and felt fine for the most part. It spins smoothly and has absolutely no play.

http://986forum.com/forums/uploads01...1381534267.jpg

I did notice a little marking/discoloration on the back side of the bearing...

http://986forum.com/forums/uploads01...1381534337.jpg

Not sure what could have caused that...

The following pictures illustrate what I have a question about - the IMSB flange.

Mine had pitting and corrosion on the back side.

http://986forum.com/forums/uploads01...1381534510.jpg

http://986forum.com/forums/uploads01...1381534529.jpg

Anyone have an idea about how this could have happened?

FWIW - it turned out that my clutch was more than 50% gone. And to make matters worse, the flywheel was also bad. (Beyond the 15mm of rotation that Wayne has written about in the 101 book.)

So I had it all taken care of. Not inexpensive, but the repair to the clutch and flywheel have transformed my car. Smoother shifting, (1st to 2nd was never smooth so I would double-clutch), and the car feels a lot tighter and more responsive. The LNE IMSB will ease my mind now...at least for several thousand miles now. :cheers:

Any feedback on pitting, corrosion or flywheel would be greatly appreciated.

Picture of the patient:

http://986forum.com/forums/uploads01...1381535557.jpg

:)

What do the seals on the IMSB say? Can you tell what lube is between the seals (any grease)?

Same story. I bought my 2000 S with 29K miles a couple months ago. Last month I had the dual row bearing replaced with the LN ceramic bearing. The flywheel was also bad. No corrosion on the bracket, though.

Just my two cents worth here, but based on the concept that IMSB bearings fail because the trapped oil becomes acidic I'm going to guess that the corrosion on the front flange was caused by that same acidic oil while the car sat. Which further suggests your IMSB ball bearings may also show similar corrosion. If you dissasemble it, let us know.

It's a dual row so you were most likely ok. I hear the LN dual row bearings have no known failures.

Corrosive wear. This is seen all the time with engines that see 30k miles in 13 years. Sitting static and having long service intervals.

Jake

Wonder if a proper IMS shaft could be developed that uses pressure lubricated bearings like the air cooled motors. Would be a final and much better solution for rebuilders. The kits that spray oil on the stock bearing seem to have found a way to get pressurized oil into that area. Couldn't a flange be developed to hold a pressure lubed bearing?

ATX, I recently relocated to Austin. Who do trust with your car?

Thanks in advance.

ganseg - It's an NSK bearing: NSK 068 6204DUA17 Japan (The 068 imprint was very tough to read, even with a magnifying glass so I hope that I'm being accurate.)

There appears to be grease on the outside of the seal, but I'm not sure what type. I wiped the bearing down with a paper towel and the grease is a dark reddish/brown color. Definitely darker than engine oil.

The bearing does not smell burnt.

I may disassemble the bearing at some point to look for damage. If I do, I'll post up some more pictures.

Thanks Jake. If you see this type of corrosive damage on the flange, I'm almost afraid to start thinking about what else could possibly be corroded internally. Any areas that you would recommend paying attention to? Please be kind if you can - as I'm finally sleeping better at night.

Snowman - welcome to Austin. Sent you a PM...

I already invented that. Watch the video and see the information here.

The IMS Solution

Glad you got it done, I still need to get mine in for surgery. The corrosion would have me concerned also about the internal ball bearings of the IMSB. Looks like a good choice to replace the IMSB:cheers:

Time for a Blackstone oil analysis?

That won't tell much other than TAN and TBN.

Jake - I have relatives in Atlanta. One of these days I would like to take a road trip, drop my car off and have your shop do a complete tear down/rebuild with some enhancements. :)

I have 7 Texas cars here right now.. A couple are here for IMSR jobs, the rest will be with me over the winter getting full reconstructions.

Well done! Any hope for double row owners short of splitting the case and sending the IMS into your shop?

t
That may not be corrosion. It looks a bit like the casting did not clean up after machining.

Not applicable to dual row owners without shaft intervention requiring engine disassembly.

Flywheel bad and clutch over 50% gone at 29k miles? Why/how? Really bad PO driver?

Totally normal.

Thats why every IMSR procedure we do comes with a clutch kit installation. These cars are hard on clutches.