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CBass · Joined: 03 Nov 2002 Posts: 2807 Location: Vancouver, Canada

My car recently started shuddering heavily when leaving a stop. I played around on a rural road and found that if I use certain combinations of gas and clutch it doesn't seem to be an issue, but at other time's it's horrible!

Searched similar threads

http://www.924board.org/viewtopic.php?t=15742&highlight=vibration

http://www.924board.org/viewtopic.php?t=12346&highlight=clutch+judder

No real definitive answer though.. I did recently adjust my ignition timing, but otherwise that's about it.

Anyone have any recent experience?
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'81 931 in various states of assembly

Tigger937 · Posted: Tue Jul 25, 2006 3:38 pm Post subject:

Had a similar experience about a year ago. I can remember a few times accelerating from a stop and noticing the RPM's revving higher than normal accompanied by severe lack of acceleration. Lasted a short time, then disappeared after a few hard accelerations. Best I could figure was that it appeared to be disc slippage in the clutch possibly due to oil, grease or some other substance leaking on the disc surface. The car had sat for quite a while (several months) which may have contributed to the problem.
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1981 931 (Concours)
1982 931 (Daily Driver)

"Think outside the box"

CBass · Joined: 03 Nov 2002 Posts: 2807 Location: Vancouver, Canada

No clutch slippage under driving, it doesn't do it if I start from a low rpm with gradual clutch slippage. I gave it a few goes with some oomph and it felt awful, looks like it's coming from the rear end for sure. Crawling under in 5 minutes. *cringe*

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'81 931 in various states of assembly

CBass · Joined: 03 Nov 2002 Posts: 2807 Location: Vancouver, Canada

Found the cause. Tranny mounts were twisted. My fault, I double checked the tightness on everything a few days ago when I noticed my boots were going on teh one axle. Looks like I tightened the nut enough that it spun the mount slightly!

So the transmission was being loaded by the side, and the mounts couldn't resist the twisting as much. So much fun! Car drives much better now that I fixed it.
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'81 931 in various states of assembly

Tigger937 · Posted: Wed Jul 26, 2006 12:32 pm Post subject:

Nice work! Always like to hear happy endings that don't cost anything.
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1981 931 (Concours)
1982 931 (Daily Driver)

"Think outside the box"