When to Replace Clutch?

[911gilley]

I have just purchased a '83 3.0 engine and have started the "clean-up" process prior to installation. I removed my clutch assembly down to the flywheel. How do I know if I need to replace the pressure plate, clutch disk, throw-out bearing, and/or flywheel.

What are the wear signs? I have photos of these items I can post if it helps.

Thanks,

-Ed

[masraum]

Is the disk bonded or riveted? How much disk until you get to the rivets or left until you get to metal? Is there any spots of discoloration on the PP or fliywheel?

Generally when the thing starts slipping is the right time to replace, but since yours is apart that is hard to determine.

Go ahead, post pictures, that will probably help.

[911gilley]

Pictures to follow.

[911gilley]

Here are pics. Any suggestions appreciated:

[Superman]

You might want to show those parts to a professional. According to my untrained eye, and judging from only photographs, I'd guess they look fine. Both the PP/Flywheel surfaces, as well as the disk itself. But again, if you show the PP and disk to a professional (leave the release bearing on the PP), you'll get a better answer.

[911gilley]

bump

[toolman]

There is a wear limit on the clutch disc, 8.1 mm +- 0.3 is new, 6.3 is limit. This is according to Wayne Dempsey's book.

[Superman]

Like I say, the friction material seems fairly thick to me in the picture, and the friction surfaces do not seem to have the darkened blemishes that indicate those parts have gotten too hot. But I'm not sure anyone can make a definitive assessment of those parts via photograph. All, and I repeat ALL of the mechanics I trust would be happy to give me an opinion on these parts if I just bring them in. The specific opinion I would seek out (and did) regarding 9111 clutch parts is John Walker. But if I were in a different city, I'd still be inclined to take them to an actual 911 mechanic. That's as much as I can help you, I think.

[911gilley]

Thanks to all who replied.

I am going to have the flywheel resurfaced this week and will ask their opinion on other parts.

I didn't think to look at Wayne's book for the wear limit on the disc. I'm assuming you mean his engine book, but I have both so I'll check it out.

[yelcab1]

You're into it this far, what's another $150 for a clutch disc. Resurface the Flywheel and re-use the PP and you'll be good for another 50K miles

[911gilley]

Yeah, it's not much but adds up on my restoration project....besides, a lot of the parts on engine I just bought look new as previous owner was in process of restoring car. I'm trying to determine how old this clutch really is, it might be fairly new (doesn't look horrible).

How do you measure the tolerance on the disc? Is this each side or both sides together?

Can the PP be resurfaced? Probably need a new TO bearing though.

[toolman]

I had my PP resurfaced and it worked out fine. They only took .004 off. Your clutch disc can be measured with a vernier caliper. Since you do not have the rubber center disc, I would say that it is "newer" and has been replaced already. If it was acting fine before you removed it, and the disc measures up, I would put it back in. It only takes a few hours to remove the engine and trans whenit does go out wich might never happen.

[911gilley]

I ordered a new Power Clutch kit from Pelican. I decided to just replace everything while I have engine out. The PP is in real good shape and disk is at 7.75 (wear limit 6.3 and new is 8.1 +-.3) using vernier caliper.....not horrible.
Anyone interested in purchasing these items let me know.
Thanks for all replies.

[kepperly]

I would reuse the clutch but rplace the T/O bearing.

Keith