jeebus31

The drive shaft flex disc on my turbo is cracked and needs to be replaced. Has anyone performed this replacement?? I am wondering if it is doable on jackstands.

Here's the part number: 99742102000S1

saabin

Local buddy of mine says it's doable on jackstands.. He did his recently when he did some work on the transfer case.

jeebus31

Awesome. Thanks very much! I think I'll do it at the same time as the trans mount in a couple weekends. I'll take photos... haven't found a DIY on the net for this particular job.

140.6er

I’m subscribed. Are your tranny mounts shot too?

jeebus31

Tranny mount is original and at 117k miles I am planning to replace it at the same time.

140.6er

Yes, I agree with replacing them. At 117,000 those mounts have to be tired. How are your engine mounts?

Bomar Shelby

Ah, the guibo, had one on my 1987 Merkur XR4Ti

140.6er

Yes, the guibo was always an issue in the older BMWs, e30, e36 and e46es. They would crack and tear over time.

jeebus31

Engine mounts gotta go too. Did that on my previous C4, pretty straightforward job. I was planning to do them whenever I got around to replacing the spark plugs and coils since the engine has to be lowered anyway.

tinkerbill

Not sure if you and the other DIY'ers are aware of this resource but Porsche has an online set of documents that have helped me a lot when working on my 997.2 TTS. The site is located at https://techinfo2.porsche.com/PAGInf...?Type=GVOStart and is the 'Porsche Integrated Workshop Information System'.
If you go through the motions of signing up, you can enter your VIN number and get all the info that is relevant to your specific vehicle. Parts lists, workshop procedures, etc. The cost varies but can be as little at $14/hour to download as many procedures as you can to your computer.
Bill

jeebus31

That seems like a great deal. I'm gonna check it out - thanks for the tip.

Ordered all the things today. Hope to get it done in about two weeks. Updates will be in my DIY thread.

bronz

was it a pretty straightforward job replacing the flex disc? any tips or special tools needed that i should know about? thanks

jeebus31

Straightforward. I removed the trans mount and supported with a jack - mine is an auto/turbo so it may be slightly different on your .2 C4S. Unbolt the flex disc from the trans output shaft - you will need to have a second person holding resistance at the tire or sit in the driver's seat to depress the brakes because those bolts are pretty tight. Then unbolt the drive shaft mount at the front differential. The drive shaft can then be removed from the diff by simply pulling. Here are some photos. Make sure to reinstall the flex disc in the correct direction. I used loctite on the new bolts. Unfortunately I do not remember the torque spec.







With trans mount and support bracket removed giving clear access to the flex disc


Destroyed


Pivoted down to remove the remaining three bolts


Removed the drive shaft to clean it up/inspect




Bolted in place


Let me know if you have any questions.

campbesl

What were the symptoms that led you to discover the bad disc?

jeebus31

Driveline clunking particularly when rolling at low speed and then accelerating. I thought it was a suspension issue until I discovered the bad flex disc. Replacing the flex disc fixed the noise.