72 Clutch Replacement/Leaky Flywheel Seal..

IAN · 08-22-2004, 10:48 AM

Quick question:

I have a 72 911T. I do not know when the clutch was replaced last. I have receipts that the engine was rebuilt around 25K ago but no paperwork on the clutch.

The clutch in general seems to work okay with one exception. If I park the car for a couple of weeks without driving it the clutch will slip for the first few minutes of driving. I believe this is from the leaky flywheel seal. I can tell the that the flywheel seal is leaking from the all of the oil muck that is gathering around where the engine mates with the transmission.

I'm planning on pulling the engine out of the car in the next couple of months and replacing the flywheel seal.

Will I definitely need to replace the clutch? Is there a way to tell if it needs to be replaced once I have removed the engine and seperated it from the transmission?

Thanks.

Jim Sims · 08-22-2004, 01:15 PM

Are you sure it's engine oil; what type of oil do you have in the transmission? The front oil seal on the transmission may require replacement (on a '72 the transmission has to come apart to replace the front oil seal). The clutch disk will have to be replaced if it is "oiled"; other parts (pressure plate, release bearing and pilot bearing) may be okay but if you have no history on them then it may be wise to replace them while you're in there. If it is the "rear main seal" then you'll need to remove the flywheel and replace the screws that secure it. Might be a good time to machine the flywheel if it is scored or damaged. Cheers, Jim

john walker's workshop · 08-22-2004, 02:06 PM

flywheel seals rarely leak. jim probably nailed it. gear oil smells more "spicey" than engine oil, so take a sniff.

Grady Clay · 08-22-2004, 02:28 PM

You should look at these two threads:

Transmission input shaft oil seal on a 69 what's involved in replacing?
and
Replacing 901 Tranny Shift Shaft Seal

We developed this extra seal protection because the ’72 915 seal was so difficult (expensive) to get to. We applied it to all other input shaft seals – 356 and later.

Best,
Grady

IAN · 08-22-2004, 05:37 PM

Will I most likely need to send off my transmission to a shop to take care of these problems or will I be able to pull this off myself? I would imagine that a transmission shop would probably want to do a rebuild while they were at it? Thoughts? Cost?

Thanks.

Ian

Jim Sims · 08-22-2004, 05:47 PM

Have you "dropped" a 911 engine/transmission before? Cost to replace the seal if you have or can borrow all the tools will be approximately $100 (transmission oil, transmission gasket kit, engine oil, CV joint gaskets, etc.). Cost to rebuild the transmission "DIY" around $800 depending upon what must be replaced; proper professional rebuild likely to be $1800 plus. Cheers. Jim