On my 89 zf6 vert I Started noticing a clunk after shutting off the car about a week ago. Traced the noise to the bell housing area and found it would go away if I pressed the clutch in. Today I did some extended driving on the car and a couple times upon startup there was a crazy knockin sound coming from the same area. I put the car in gear, slowly released the clutch and it went away. It will not make this noise every time. Out of 10 startups it happened twice.
I think it's safe to assume the flywheel is the culprit, the flywheel you can no longer find for sale anywhere.
Now my issue is a replacement clutch kit. I have looked at the spec kits but the Internet is plagued with horrible reviews on their products, then I was looking at a ram kit and I can't see any info anywhere on whether or not the new hydraulic slave comes with the lines required to change to this system. The supplier I use at my shop says he can get me a fidanza flywheel and luk clutch kit but i work on mostly european cars and think this might be out of his expertise and I don't want a hoist down for this job if he's wrong.
I do not race this car,it's a weekend driver on sunny days only, all stock, however I'm slowly building a 383 for it and want this new clutch to hold up to the 350-400 hp I'm planning it to put down.
I looked under the car and it appears to be a black tag tranny.
Any help or suggestions are appreciated

 

Call the nice folks at Carolina clutch, they will take care of you.

 

Could also be the throwout bearing, the input bearing on the transmission, or even the pressure plate. It could even be as simple as the clutch fork pivot stud backing out resulting in some light interference.

Before spending a bunch of money, I'd pull the transmission and have a look.

Just my $0.02

 

So here's the update,
Spoke with Carolina clutch and he has a kit for $760 which includes everything you need however you have to get the steel flywheel match balanced. Got off the phone and started wondering how they would match balance a pooched dm flywheel. A call to the machine shop confirmed there is no point trying as a bad dm flywheel will never give an accurate reading.
Second option is a ram conversion clutch kit. The guys I get all my corvette parts from have this kit for $890. They claim the flywheel in this kit is already balanced to factory specs and the kit comes with everything you need. They also told me they have sold lots of these clutches and never had one come back or had any complaints.The only issue I have is the guy at carolina clutch told me he's heard of issues with the install of this clutch and guys who put them in have pulled them out in favour of his kit. He sounded like a straight up guy and not the type to bs so now it's got my head spinning.
This is starting to become a thorn in my side because I just want to buy a direct fit kit and get this job done. I'm not as concerned with the price as I am with getting the best parts because im very picky with my car and most importantly I can't have this car tying up a hoist.
Anyone here gone thru this and have any suggestions ??

 

I appreciate what your saying but if I pull the tranny Im putting new everything in one way or the other. I'm doubtfull of the input shaft bearing being the issue as I have no gear noise at all, shifting issues, noisy engagement, or noise on decel while in gear, all of which can be signs of a bad input shaft bearing. It will cost me less money to buy all these parts and be prepared than if I have a hoist tied up because I'm not.

 

I went throught a DMF and clutch issue when I bought my car two years ago...

I ended up buying a good used DMF and used a clutch kit from Carolina Clutch.

A little while later, spec came out with their match balanced SMF that weighed in the same as the DMF...

I would have bought that new smf with the sprung clutch kit and called it a day...

I do have a spare DMF that is ready to go and in great shape, but would only let it go for a bit more than what I paid (250)...

Mike