Question concerning rear main seal and clutch (83 SC)

[curlesw]

I am fairly confident I have a leak at the rear main seal and have found numerous posts/tech articles on the repair process. But my question is this, since I have to remove the clutch to get to the rear main seal, are there clutch components I should replace as part of this process? Of course when I remove the clutch I’ll snap some pictures and post them so get an assessment of the wear. But are there some parts that “must” be replaced as part of the clutch removal/installation process?

Supposedly a new clutch was installed when I bought it (no documentation available, ~ 50k miles ago). The clutch seems fine, no problems…the car is a daily driver.

The offending RMS:



Thanks.

Wayne C.
83 SC

[Peter Zimmermann]

Is that oil, or some sort of cleaning fluid, on your exhaust?

[curlesw]

Originally Posted by Peter Zimmermann

Is that oil, or some sort of cleaning fluid, on your exhaust?

That's oil...from my other leak

It's coming from somewhere up top. I "thought" I had fixed it, evidently not, get to try again....

Wayne C.
83 SC

[Superman]

A widely respected Porsche mechanic once told me that 911 rear main seals almost never leak. He says that oil on the clutch disk usually, or perhaps always, means a leaking transmission input shaft seal. Makes sense. Oil would have a hard time getting onto the clutch disk from the engine. FWIW. maybe you do have a leaking rear main seal. But apparently, that is unusual. If you replace it, use the brown seal.

Clutch disks are not cheap, but if it were me I'd replace it at this time. 80K is about what you get on a clutch disk. Having a thinner disk in there causes the clutch pedal to feel heavier. At a minimum, I would replace the disk. And I would at least inspect the rest of the clutch parts. TOB, guide tube, fork, pilot bearing, etc. Take them to a Porsche guy for inspection if you're not sure what to look for.

[Rot 911]

I agree with Supe on changing out the clutch.

[curlesw]

Thanks guys…I’m venturing into unknown territory here so once I get the clutch off I’ll have a better idea of what I’m dealing with, either a rear main seal or transmission input shaft seal.

The clutch does “feel” heavy so I’ll look into a new disk at a minimum.

Thanks much.

Wayne C.
83 SC

[RoninLB]

my old thinking is that tranny oil on the disk means a new disk.

I'm assuming that's still true and there's no magic solvent available to clean them?

[sparkle84]

My rear main (flywheel) seal was leaking & the clutch disc was completely impregnated with oil. Input shaft seal was fine. Replace the disc at the very least. Complete kit would be advisable. If you figure in your labor & have to do it again in the near future you'll wish you had. Basic 3 pc. kit's usually all thats needed. Inspect other parts for wear. Most will probably be OK. Pilot bearing is a good idea. Replace the fork shaft seals & if the guide tube's worn, as it will be, you can turn it 180 degrees unless it looks really bad. Should run you about $700. including resurfacing the flywheel.

Good Luck!!

[Superman]

Originally Posted by sparkle84

My rear main (flywheel) seal was leaking & the clutch disc was completely impregnated with oil. Input shaft seal was fine. Replace the disc at the very least. Complete kit would be advisable. If you figure in your labor & have to do it again in the near future you'll wish you had. Basic 3 pc. kit's usually all thats needed. Inspect other parts for wear. Most will probably be OK. Pilot bearing is a good idea. Replace the fork shaft seals & if the guide tube's worn, as it will be, you can turn it 180 degrees unless it looks really bad. Should run you about $700. including resurfacing the flywheel.

Good Luck!!

I'm certainly not making judgements about your diagnosis but again, rear main seals 'almost never' leak, according to my source. Plus, if you think about it, a leaking rear main seal would still have a hard time soaking a clutch disk. The oil would run along the back of the flywheel. But if a transmission input shaft leaked, the oil could crawl along the shaft and find the clutch disk easily. Your mileage may vary, of course.

[curlesw]

Originally Posted by RoninLB

my old thinking is that tranny oil on the disk means a new disk.

I'm assuming that's still true and there's no magic solvent available to clean them?

thanks, good to know.

Originally Posted by sparkle84

My rear main (flywheel) seal was leaking & the clutch disc was completely impregnated with oil. Input shaft seal was fine. Replace the disc at the very least. Complete kit would be advisable. If you figure in your labor & have to do it again in the near future you'll wish you had. Basic 3 pc. kit's usually all thats needed. Inspect other parts for wear. Most will probably be OK. Pilot bearing is a good idea. Replace the fork shaft seals & if the guide tube's worn, as it will be, you can turn it 180 degrees unless it looks really bad. Should run you about $700. including resurfacing the flywheel.

Good Luck!!

Thanks, will check them all.

v/r
Wayne C.