I would appreciate any help from the seasoned mechanics...I have a 83 z28.only 66k orig. miles, and last year I noticed whenever I took my car on the freeway for around 25 miles and then came back into a city, when I stopped at light, then started again in 1st gear, the car would chatter like crazy, so I took it to local trans shop, they said needed new clutch, so had them install a new I think it was called something like Lutz clutch, said it was one of the best for normal clutches. i do not hot rod mine or slip it anytime. After a few months I took it onto freeway, and came back into town, and same thing..lots of chatter...so I took it back, and they replaced it with another new clutch...well you guessed it...went for another freeway ride, got back into town, and chattered bad, and it was increasing getting harder to get into gear, and occasionallly it would grind a little going into third, which was strange. Here is the kicker, as a little time passes, I drove my car home when it was cooled down, and it drove just fine, no chatter, shifted fine, only seems to happen after freeway run. The mechanic said I could bring it back monday and they would look it over....but am preplexed...I specifically asked them is the rear main seal ok, Yes...I may put half quart in every 3k miles, no puddles on ground, and I asked them if they turned flywheel, and they said yes, and asked them if the bushing on the inpujt shaft on the trans was good, they said yes.....I asked them if all mounts were good, they said they did not check them....but even if it was loose, would it not do it all the time? Anyway...what else could possibly be wrong?????, the trans seems ok, no problems that I know of, just really needs some ideas so when I take it back in monday moring, I can make sure he checks any other items that anyone on 3rd gen. comes up with...again, love my Z, and if anyone could help me find this culprit it would be much appreciated. Thanks, Dennis

dennisgramm@verizon.net

 

83 has mechanical linkage for the clutch correct? maybe it needs adjustment, the only time i experienced clutch chatter is if the clutch disc is bent or the pilot bushing is worn

 

Had the same problem. The z-bar ( also known as a bell crank)
had cracked and was slowly bending over time. This caused clutch release to get harder till it wouldn't release at all. I got another z-bar and all was fine till it broke. (seems the bushings inside it were shot) But it would work fine till the clutch got hot, like in stop-n-go traffic, than quit realeasing. Good ol smell of clutch burning. You can't get another one, they quit making them.
I fixed my 83 by converting her over to an 84-92 hydraulic setup.
Good luck.

 

Another thing to consider in addition to above suggestions.....

New flywheel with the new clutch?

Flywheels get heat-warped over time/use. The heat and pressure during use warp the metal. You can machine them flat again (which happens when they are cold, obviously) but as soon as they get significant heat in them again the metal somehow "remembers" the warping and returns to it, giving you a lumpy clutch engagement again only when hot- perfectly smooth when cold. I never resurface a flywheel that has ever had a problem with clutch chatter in the past- I always replace them with new.

 

Good point, notice my sig...I'm now running a Hays 30lb billet flywheel