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IMS bearing failure for your 996, Y or N? tell us (yr, 996 Mk1 or MK2 failure mode)

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IMS bearing failure for your 996, Y or N? tell us (yr, 996 Mk1 or MK2 failure mode)

Old 02-03-2013, 10:41 PM
Marc Gelefsky
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Default IMS bearing failure for your 996, Y or N? tell us (yr, 996 Mk1 or MK2 failure mode)

As requested I have posted this poll.

Many have been asking to understand how many of the 996 cars have had IMSB (intermediate shaft bearing) failures. Although the people on this board are not necessarily a random sampling of 996 owners many have asked to see a poll to get a better sense of it.
  • Please vote only once for each 996 you own (yes or no).. you can post multiple times but only vote once
  • Please include details of your car and engine if it failed via IMS and when.
  • Please let us know if there were any mitigating factors (low oil, overheat, etc) that might have led to the failure
  • Please post only about IMS failures, this is not about RMS failures
  • Please post only for your car, no heresay or posting for a friend who doesn't frequent the board
  • Please post what was done to rectify the failure if your car failed (CPO engine, engine out of pocket, used engine, sold, insurance fire, pushed it into a river etc)

Please ONLY POST DATA HERE. Not discussion.

Hopefully this will help owners and soon-to-be owners get a sense of how frequently this occurs.

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Old 02-04-2013, 12:29 AM
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49k miles currently. Not yet.
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Old 02-04-2013, 12:46 AM
street rod
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2001 C4 - 62k and no issues. I proactively installed an LN dual row bearing and now have 68k and still running good.
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Old 02-04-2013, 12:49 AM
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1999, No failure of Dual row IMSB, but preemptively replaced with LN ceramic at 60,000 miles.

Original IMSB still sealed and showed no signs of wear at 60,000 miles.

Original motor, not a replacement.
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Old 02-04-2013, 12:50 AM
Steve's MLC
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No issues. Replaced for peace of mind with LN at around 58k. IMS is on my desk at work and I tell people it's a $15k part.
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Old 02-04-2013, 08:09 AM
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No issues on my 996 mk2 40th anniversary.
As many veterans of this forum know, these polls suffer from selection bias, incomplete sample size, unknown denominator, fake posts, etc.
But some data is better than no data.

Here is my contribution to the data with a known denominator due to the 40th anniversary fixed production. In our series, it is at least 0.5%.

Here is the 997 forum poll data which is around 5%
If fake posts present a problem in the future, we could always do just a poll with Rennlist members...
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Old 02-04-2013, 08:40 AM
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'99 original dual row with 200 000 miles. Replaced it with a hybrid dual row (From Boca Bearings). Old bearing still looked and felt good.
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Old 02-04-2013, 08:44 AM
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IMS or IMSB? Perhaps the title should be updated even though most know it is IMSB.
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Old 02-04-2013, 08:48 AM
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70,000 mile on a dual row bearing and no problems. At 50,000 mile when I had the engine dropped to fix a cracked head/intermix I did replace the IMS flange with the updated flange and removed the seal on the bearing. Next time the engine is out or the trans is dropped I do plan on installing the LNE bearing.

Last edited by Dharn55; 02-05-2013 at 11:18 PM.
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Old 02-04-2013, 09:08 AM
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70.000 miles on OEM bearing. 2004 996 C4S Cabrio.

Had the the IMS flange replaced (+RMS) 1.000 miles/3 months ago at local OPC. At the time I didn't have enough knowledge to ask the OPC how the IMSB was or if they have replaced the IMS flange because they "were in there"... Just knew I had a leak and asked them to solve it...

They just suggested replacing the clutch at the same time, which I did.

I estimate doing 5.000 miles at max this year, so maybe next service I will ask the OPC to replace it for the LNE or the INSARO IMSB. On the other hand, I have read at 911uk forums that Hartech (major UK M96 rebuild specialist) doesn't like to replace IMSB on currently "good" running 996's...

This IMSB thing is a bit confusing to a newbie 996 owner like me...
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Old 02-04-2013, 09:20 AM
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2002 27k mi and no issues

My old 1999 I owned for 3 years and 50k mi and no issues on that one either
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Old 02-04-2013, 09:32 AM
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118K and climbing. Motor is original along with everything in it.
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Old 02-04-2013, 09:37 AM
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2000 996 with 119,000 current. Proactively replaced with LN dual row. Old bearing was good to go.
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Old 02-04-2013, 09:38 AM
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2000 C4 tiptronic 110K original engine and bearing still going
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Old 02-04-2013, 09:40 AM
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DD and tracked 2002 996 with 125k km. Proactively replaced with LN. Old bearing was good to go but need an engine rebuild (worn out cylinders).
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