Clutch Question

C4VetteGuyOKC · 10-31-05, 09:22 AM

I'm getting ready to put a new clutch in my 91, as it's starting to get a little weak. I've read on a few other boards, that when most of these guys replace the clutch, it's almost mandatory to replace the flywheel too.

My question is WHY? I would think that the OEM steel flywheel would be much more durable than an aftermarket flywheel. I really don't want to change the flywheel, and see no sense in it.

Answer/Advice? TIA!

JonM · 10-31-05, 09:55 AM

I changed my clutch about 10 years ago and had the shop take a cut on the old flywheel and its worked perfectly. Check the condition of the flywheel, make sure its not cracked or warped...run a straightedge across it in a few spots, it should be nice and flat with no grooves from the bad clutch.

Vettelt193 · 10-31-05, 10:28 AM

Quote:

Originally Posted by C4VetteGuyOKC

I'm getting ready to put a new clutch in my 91, as it's starting to get a little weak. I've read on a few other boards, that when most of these guys replace the clutch, it's almost mandatory to replace the flywheel too.

My question is WHY? I would think that the OEM steel flywheel would be much more durable than an aftermarket flywheel. I really don't want to change the flywheel, and see no sense in it.

Answer/Advice? TIA!

The flywheel on the ZF6 tranny can't be re-surfaced. If you are pro-active about replacement (as it sounds like you are) and replace the clutch before it blows out, you will probably get away with changing the clutch alone. If the clutch blows out, you will probably have to get a new flywheel.

I don't think it is an almost always scenario... it is a case by case basis, and only almost always when the clutch blows out.

redvett · 10-31-05, 10:33 AM

The flywheel in a ZF car is a dualmass flywheel and isnt resurfaceable.

C4VetteGuyOKC · 10-31-05, 01:14 PM

Quote:

Originally Posted by redvett

The flywheel in a ZF car is a dualmass flywheel and isnt resurfaceable.

My god, a new one of those must cost a small fortune.

redvett · 10-31-05, 02:34 PM

Quote:

Originally Posted by C4VetteGuyOKC

My god, a new one of those must cost a small fortune.

I never heard anyone say Corvette's were cheap. Looks like $2000.00 list. for the dualmass.

scotch1 · 10-31-05, 05:54 PM

Not so.
My mechanic quoted me $1500.00 for an OEM flywheel for my 90 c4..
I posted on this board and Chris gave me the nimber of Clutch Express and called them and got a better deal.
I looked around e-bay and found a dual mass from the partsladi for $685.00, that's less then half of what my local mechanic quoted me.
Let me know how you made out.
scotch1

C4VetteGuyOKC · 10-31-05, 09:13 PM

I can get the OEM DMF from Carolina Clutch for $685. It'll be about a grand for the complete clutch/flywheel setup.

Was also told that I could convert to a single mass flywheel, and a clutch setup with the sound dampener in the pressure plate for around $750.
The only drawback to the second option is that it's more for aggressive driving, and I'll get a little more transmission noise.

A tech support guy at Southbend Clutch told me that if I replace the clutch before it goes out, I shouldn't have to worry about the flywheel at all, as at 69,000 miles, it should only be through half it's expected life.

At least I have options. It'll be a cold day in hell, before I pay my friendly neighborhood Chevy dealer $2000 for a freakin flywheel.

MBDiagMan · 11-01-05, 09:40 AM

If I were you I would definitely not buy a new flywheel until after the clutch is out so that you can inspect it first. Unless someone who has been driving the car who is not good in handling a clutch, it is very likely that it will not need to be replaced.

Good luck,

rkew · 11-02-05, 09:06 PM

I replaced the original clutch and flywheel on my '91 this May (76,000 miles). After removing the flywheel, putting it on the bench, and laying a straight edge across it, I found it to be too dished out in the center to risk re-using (over 1/8th of an inch difference between the center and the outer edge). If you're doing the job yourself (and you haven't done it on that car before), you'll probably come to understand why a person becomes risk averse about using questionable parts by the time everything is apart. It's a bear of a job and you don't want to do it twice, especially because you skimped on something.

And whatever you do, make sure to mark the relationship of the pressure plate to the 6 ears on the flywheel. In particular, the location of the paint dot on the pressure plate to it's corresponsing ear on the flywheel. I recommend numbering every pressure plate hole and every ear on the flywheel before you unbolt the pressure plate. If you use OEM or OEM-like parts, the paint dot on the new pressure plate must go back on the same ear on the flywheel to maintain proper balancing. The flywheel is keyed so it can only go back on one way, but the pressure plate can go back on the flywheel six ways - and only one of them is right.