I've seen a variety of clutch threads. Everyone seems to have a different opinion on wheather the flywheel should be resurfaced.

I've got a '92 6-spd. What's the verdict? :confused:

 

YES- They can, and should be resurfaced if your installing a new clutch. They require a special technique, so make sure the shop your having it done at knows what their doing.

 

I would consider a single mass flywheel... much nicer. a little louder, but a lot better. lighter, more direct. DRM has an iron one for sale at 249.00 or so.

the other problem, the counterbalance has a tendency to wear out...


[Modified by bogus, 11:45 AM 1/17/2002]

 

Some shops will do it, other will not. The machinist does have to be careful, as it is not advisable to remove much thickness. if too much is machined off, depending on your clutch disc you can end up with insufficient clutch disc hub to flywheel/pilot clearance. Some here will disagree, but I would seriously advise against the single mass unless you are a dedicated road racer who is adept at heel/toe downshifting (check around and you will find people who switched BACK to dual mass after a single mass conversion). If the GM price for dual mass replacement flywheels is out of budget, check with the aftermarket suppliers in your area - I understand that there are aftermarket dual mass flywheels in the $500 range. The heavier dual mass flywheel is actually better for launching a stick car at the drags (note that the aftermarket offers "heavy" flywheels for drag racing, and light flywheels for road racing).

Thomas

 

I wouldn't have it resurfaced. I had mine done last year and I regret it. The factory doesn't recommend resurfacing, just replacement.

 

Does this answer your question? :D

 

Clear as mud! :D

I'll probably have it resurfaced because I have little choice (I can barley afford to put the clutch in right now :( ). I question the factory. Of course they want you to replace it, they want you to buy a new one from them.

I am curious as to the differences. Some have said you can re-surface it 2 or 3 times, others say no, don't do it.

MOJO: What don't you like? Does it not hook up right?

 

I have to let the pedal all the way up before it grabs, I can't stand that. Everyone else who did it had the same problem. I was told you can't adjust it. I'm used to it now, but I prefer to have it "grab" just as I lift from the floor.

But $900 for a GM flywheel was the reason I resurfaced, just couldn't afford it at the time.

 

[QUOTE]I have to let the pedal all the way up before it grabs, I can't stand that. Everyone else who did it had the same problem. I was told you can't adjust it. I'm used to it now, but I prefer to have it "grab" just as I lift from the floor.QUOTE]

I know several people with a factory resurface job. They got it done locally at RP Motorsport of Atlanta. I've driven a few of their cars on different occassions, and they felt just like stock, just gripped alot harder. Several tuner's recommend it (SGC, Exotic Muscle, etc.). I think its a matter of finding a shop that knows the trick to doing it correctly. If you wanted to make sure it was done right, think about sending the flywheel to Aaron Scott at SGC. He definately could do it right for you.
I wouldn't go with a single mass either. The negatives overun the positives IMO. I'll get my power somewhere else. :yesnod:

 

OK, what are single mass flywheels and dual mass flywheels? Whats the difference? :confused:

 

Dual mass is the factory fitted flywheel, it is not one solid piece like a conventional single mass flywheel. The dual mass has internal gears and has a viscous fluid inside. No need to spend big bucks for a single mass flywheel, just get a same year Z28 flywheel and have your local machinist flycut the clutch disc surface down to the same installed height as your dual mass flywheel.

I am one of those guys who converted to a single mass flywheel, and then converted back to a dual mass. Although many performance minded people would pay no attention to the sound of rocks in a coffee can at idle with a single mass/ZF combo, I decided that I much prefered NOT to have to explain to everyone that my Corvette 'wasn't about to lose anything - just a noise from a stupid racing modification".

Since the clutch has no real adjustment it is important to only slightly machine the surface of a dual mass flywheel, major surfacing WILL make your engagement point wacky.

Side note: if there is air in your clutch's hydraulic system, or if the master or slave cylinder have internal leakage - this too will cause a wacky engagement point. Probably more Corvettes with only badly performing hydraulics get misdiagnosed as needing a clutch replacement - seriously, many mechanics will only think of servicing the hydraulics if there is an obvious external leak.

Thomas

 

I vote no :nono:

 

I toasted one so far, 104,000k miles. The new ones are soooo expensive, that I got a used one off a low mileage wrecked corvette at a vette salvage yard. Half the price. I too have heard NOT to touch 'em. Mine just got lightly sanded w/ heavy grit I think. It arrived shiny.

 

Someone posted a note on this last year about a guy who had one resurfaced. Apparantly the cutting fluid and heat from the resurfacing process weakend the flywheel assembly enough so that it flew apart a few months after it was reinstalled in the car. This is the reason GM states that the flywheel is not resurfaceable. I am surprised that any machine shop would even do the work and risk being sued later on.

 

...sigh...

taking 5 or 10 thou off the surface will pose no danger of it later flying apart.

taking 125 thou off the surface IS asking for trouble.

If you have deep gouges, resist the temptation to remove all traces of the gouge. Otherwise, I like to have a nice true surface for a new disc.

I would like to hear from ANYONE who has real firsthand knowledge of a dual mass flywheel coming apart. I've known them to get loose internally and really start clanking, but I've never seen them come apart. In years past I have seen a clutch/flywheel explosion where the flywheel exited the car - but this was on an old time drag car.

Thomas

 

I have a star engineering SPEC stage III carbonfiber clutch with an aluminum singlemass flywheel. Its actually rather easy to launch at a drag strip. (although You do have to bring the rev's up a bit) Alot more controlable. the clutch is designed to do this and the flywheel is engineered not to rattle like the single factory flywheel kits do GM wants $800 for a dual mass $950 is what I payed for the throwout bearing, clutch,Pressureplate and flywheel. I really like this clutch. The downside is that you have to slip it some to get the car moving on the street. (kinda like an mid 80'sto early 90's 5 liter mustang)

 

Anything "can" be ruined by an incompetent machinist. A sharp cutting tool will not overheat the flywheel, as suggested above. You can hold the metal with your hand when it's being cut. A clutch burning from a 400 HP motor twisting it might cook it. I would ONLY cut the flywheel if it was scored by clutch rivets and if you remove much metal it will be ruined. A narrow (1/4"), shallow score mark will not adversely affect clutch performance or wear and can be ignored. Hot spots and cracks can not be removed by cutting. I have seen aftermarket suppliers for the dual mass in the $600 range.

 

Can you elaborate more on this? To my knowledge the only solution to dampen some of the noise from a single mass is to use a sprung hub.

Thanks

 

I just bought a brand new dual mass at Carolina Clutch for $618. Call Tom and tell him that Mark sent you.

:-)

Mark Monroe
Harrisburg NC

 

The reason the throw out bearing rattles is because the single mass flywheels moves the pressure plate, Clutch disc and throwout bearing closer to the engine(further up the input shaft) the aluminum flywheel is machined to stay the same depth as the dual mass so the bearing doesent vibrate and rattle. With a single mass conversion you have to change the depth of the clutch fork with a new ball piviot. You dont have to with the aluminum flywheel.