Clutch Advice, Reuse or Replace? Options

[mzapisek]

I have very low mile original 1.7 (30K). I recently installed a 4 post lift and have begun doing all the 50 year service updates (SS fuel lines, shift bushings, engine refresh etc.). I am certainly a novice mechanic at best. The information on this board most definitely helps close the knowledge gap and encourages me to self perform tasks I would otherwise be unsure of. While inspecting the flywheel, clutch and pressure plate they appear to be in very good condition (no grooves or obvious signs of wear) just some slight discoloration.

Should I reuse or replace? I did purchase a new rear main seal but I do not see any signs of a leak. From other info I have read on this board the newer seals are/maybe somewhat substandard. While I welcome the opportunity to fix everything I can while the engine is out and on the stand don’t want to perform unnecessary work or look for problems that don’t exist.

Would appreciate some advice.

Thanks.

[Superhawk996]

I’m going to go back to the original premise of the post.

What OP has posted:
Claimed 30k original miles.
He has owned car for 20 years
Posted photos show non OEM clutch
Photos appear to show at least 2mm or so lining depth above the rivets
No grooving in flywheel or clutch
No rear main seal leakage

What can be inferred from info provided above:
Owner rarely drives this car or it would have more than 30k miles in 20 years of ownership.
Clutch that came out of the car has much less than 30k miles on it.

What we don’t know:
Were the pilot bearing / RMS / felt seal previously replaced when the clutch disk was?
If yes, then all those parts are far newer and would have far less than 30k miles on them and likewise they would not be 50 year old parts.

So now we are down to the key questions:
Does the clutch meet thickness specification?
Should you disturb the flywheel to replace the RMS?

On thickness spec question - only the OP can answer that. Porsche establishes wear specs. It is black or white. Meets or doesn’t meet. There is no sense replacing parts that are in spec. Especially on a clutch we know has less than 30k miles on it.

On the flywheel / RMS question.
Consider that the flywheel / pressure plate were balanced as an assembly. If the flywheel is removed it MUST be indexed to the crank and hopefully the pressure plate was indexed to the flywheel. If not - OEM balance will be degraded or lost. The only way to regain it would be to send the flywheel and pressure plate out for balance.

Removing the RMS has it’s own risks of future leakage even if the seal is replaced. Especially if the flywheel and pressure plate become imbalanced.

Flywheel pilot bearing. If it is 30k miles on it (or less), has grease in it, and spins freely, it is fine and probably a better quality bearing than anything currently coming out of the aftermarket.

Other considerations:
Environmental / sustainability - if we / you / OP are committed to this concept - why throw away good parts (assuming they meet spec)? Consider the energy used to mine and transport all the raw materials we are talking about. OP - feel free to send me that clutch - I’ll gladly reuse it if meets thickness spec. (IMG:style_emoticons/default/laugh.gif)

So what would I do?
If clutch / flywheel / pressure plate meet spec - put it back together.

RMS - this is one of the few times that I’d say if it isn’t broke - don’t fix it. There are a lot of variables in a RMS replacement that can get messed up. Especially by a novice mechanic. A good part of the advice is based on how little this car actually gets driven.. If I were taking about a daily driver - I would do it. Clutch work / RMS is so easy to do on a 914 - if it leaks in the future fix it then. By then OP will be a bit more experienced mechanic.

[iankarr]

I’m going to go back to the original premise of the post.

What OP has posted:
Claimed 30k original miles.
He has owned car for 20 years
Posted photos show non OEM clutch
Photos appear to show at least 2mm or so lining depth above the rivets
No grooving in flywheel or clutch
No rear main seal leakage

What can be inferred from info provided above:
Owner rarely drives this car or it would have more than 30k miles in 20 years of ownership.
Clutch that came out of the car has much less than 30k miles on it.

What we don’t know:
Were the pilot bearing / RMS / felt seal previously replaced when the clutch disk was?
If yes, then all those parts are far newer and would have far less than 30k miles on them and likewise they would not be 50 year old parts.

So now we are down to the key questions:
Does the clutch meet thickness specification?
Should you disturb the flywheel to replace the RMS?

On thickness spec question - only the OP can answer that. Porsche establishes wear specs. It is black or white. Meets or doesn’t meet. There is no sense replacing parts that are in spec. Especially on a clutch we know has less than 30k miles on it.

On the flywheel / RMS question.
Consider that the flywheel / pressure plate were balanced as an assembly. If the flywheel is removed it MUST be indexed to the crank and hopefully the pressure plate was indexed to the flywheel. If not - OEM balance will be degraded or lost. The only way to regain it would be to send the flywheel and pressure plate out for balance.

Removing the RMS has it’s own risks of future leakage even if the seal is replaced. Especially if the flywheel and pressure plate become imbalanced.

Flywheel pilot bearing. If it is 30k miles on it (or less), has grease in it, and spins freely, it is fine and probably a better quality bearing than anything currently coming out of the aftermarket.

Other considerations:
Environmental / sustainability - if we / you / OP are committed to this concept - why throw away good parts (assuming they meet spec)? Consider the energy used to mine and transport all the raw materials we are talking about. OP - feel free to send me that clutch - I’ll gladly reuse it if meets thickness spec. (IMG:style_emoticons/default/laugh.gif)

So what would I do?
If clutch / flywheel / pressure plate meet spec - put it back together.

RMS - this is one of the few times that I’d say if it isn’t broke - don’t fix it. There are a lot of variables in a RMS replacement that can get messed up. Especially by a novice mechanic. A good part of the advice is based on how little this car actually gets driven.. If I were taking about a daily driver - I would do it. Clutch work / RMS is so easy to do on a 914 - if it leaks in the future fix it then. By then OP will be a bit more experienced mechanic.

As usual, Superhawk has applied great deductive logic. Agree that the amount the car will be driven is a key factor as well. As for re-using the clutch disk, is there a downside to how a used clutch disc will “mate” with a new or resurfaced flywheel? I’ve never done that before. Will they eventually match to each other?

[Superhawk996]

As for re-using the clutch disk, is there a downside to how a used clutch disc will “mate” with a new or resurfaced flywheel? I’ve never done that before. Will they eventually match to each other?

Just to be clear I’m proposing reuse of parts as-is (if in spec) without mixing and matching. So flywheel, clutch, pressure plate wear patterns will match up.

Back when I was in college and didn’t have much cash, I did mix & match out of necessity. No problem with the parts I had available. Honestly, mix and match wouldn’t be my first choice today, but I do standby the statement that I wouldn’t hesitate to reuse that clutch based on what I see in the photos.

The analogy is have you ever replaced brake pads with out replacing or turning the rotors? Not ideal but the pads pretty quickly wear to match the rotors. The downside being as they first begin to bed in, you don’t have full contact. It can lead to hot spotting of pads and rotors if not gently bedded in initially. Not ideal but it gets done more often than most of us will admit to.