I have to get my flywheel turned but don't know what the lowest measurement is allowed to still be able to use it. I have a 94 6spd. The flywheel is used, going to match up against a new stock clutch. My dual mass flywheel needs to be turned. So my question is does anyone know the lowest depth my flywheel can have before I have to throw it away? I want to make sure the shop doesn't turn it past those numbers. Thanks in advance

 

Do you know for certain that your shop is willing to turn a DMF?

Most won't. The "expert" says you can't.

 

Maybe in this modern age it is not such a probablem anymore.... but if your shop has not done a dual mass before and treats it as a single. you will needs a new dual mass, which are getting hard to find.

I know of maybe 2 guys who had them turned with good results.

Personally I would check the movement of the 2 masses to see if it is still good, and clean it up with fine sand paper or scotch brite and be done.

My shop F'd mine up when I rebuilt my engine. I didn't know untill I fired up the car, and nasty sludge came out of the bell housing. I had to pull out my new engine, get a new flywheel, and have it all rebalanced. clean out the bell housing and get the nasty oil off my brand new centerforce clutch. But this was 11 years ago.

 

where did the sludge come from? Well I will take a pic of the flywheel and post a pic and you guys can tell him if it looks horrible?

 

The sludge is inside the dual mass flywheel.

there are 2 parts to the flywheel. I asume the sludge is some sort of dampner, or lube. there is a rubber seal inside of there that holds it in.

upone first fire up, centrifugal force pulled it all out.

 

I suspect you'd be better off trying to find a salvage DMF with low miles. There are a couple of well-known salvagers, our C4Parts4Sale forum, plus fleabay.

How many miles is on ur DMF?

 

My flywheel I bought used with about 40k on it. I will post a pic because I am not even sure its a DM...I was told it was..If it is no good, which flywheel should I go with? I have a stock NEW clutch..and I don't want the chattering feeling anymore

 

In the FSM there is a test procedure and acceptable results.
IIRC there is a heavy single mass available that has the same abilities to dampen the noise.

 

I believe it's SPEC that has a heavy-weight single mass available reported to have similiar dampening qualities. Hard to say if it's any better than other heavy steel SMF's. No one has reported back on it that I know of.

 

I will post a pic tomorrow morning of the flywheel. So you guys can tell me what it is really and how it looks. I just don't want to mix a clutch and flywheel together. I would like to have a good flywheel that matches well with the stock new clutch

 

I recently installed the new Spec heavyweight billet steel SMF in my '94 LT1 car, along with a Spec Stage 2 clutch kit. So far, I'm very pleased with the results, and can report that I've heard zero gear rattle from the ZF. You might want to consider this SMF as a replacement for your DMF.

Live well,

SJW

 

I was curious about the Spec setup myself, as I am sure that this will be a near future project. I do know they are a bit pricey, though perhaps still cheaper than a new DMF.

I have also heard of using the f-body steel fly wheels, but they have to be milled down something like .030 to fit in the ZF housing, and of course match balanced. I would also imagine that one would want a sprung hub clutch if going with a single mass.

Although it is recommended that the flywheel not be machined. Actually it is recommended that it be replaced with the clutch, at least that's what GM prices a clutch replacement at. But it is possible to sand the surface smooth. Not sure what the movement tolerance is, I think I read 1/2 inch?

 

I thought the Spec prices were quite reasonable, especially when stacked up against the price of a new OEM DMF (if they were still available, which as I understand is no longer the case). I paid just under $800 for their Stage 2 clutch kit and heavyweight billet steel SMF. This included new T/O bearing, pilot bushing (which I elected to not use, opting instead for a replacement OEM roller bearing), pressure plate, disc, pressure plate bolts, flywheel bolts, and cheapie plastic alignment tool. That's a lotta stuff for eight C-notes, especially since these are quality parts. We're not talking Autozone parts here.

I've learned to take nothing for granted, so I took the new Spec SMF, and the old DMF, to the House of Balance, and had the balance checked to make sure I didn't end up with a vibration problem. LT1 flywheels are not neutral-balanced, and I didn't want to tear this car apart again if I learned the hard way that the new SMF wasn't offset-balanced correctly, especially since I was doing the job on a Kwiklift, which was only one step above doing it on jackstands in terms of the difficulty factor.

The as-received balance match of the new SMF to the old DMF turned out to be almost dead-nuts on, requiring only a tiny drill divot to match the old DMF perfectly. I have zero discernible vibration, and given the minuscule adjustment made at the balance shop, I can't imagine I would have had any vibration if I'd have bolted everything in straight out of the box. It seems that Spec paid adequate attention to proper balancing of all of these parts.

Yes, you definitely want a sprung-hub disc if you're going to switch to a SMF. The DMF has damping springs in it. Obviously, you'll lose that if you switch to a SMF.

Live well,

SJW

 

Upon further review, you're right SJW. The Spec setup does actually look like good value. How is it in terms of street manners, stop and go traffic that is? Not trying to hi jack here as I'm sure that the info may also be useful to the OP.

 

http://forums.corvetteforum.com/1569110972-post48.html

http://forums.corvetteforum.com/1569106833-post31.html

 

Nice write up, you just sold me the Spec setup when the time comes!!

 

Just ordered the spec Steel flywheel with XTRA mass and the stage 1 clutch. I am very excited to get it in and mount these things. With a new clutch and flywheel is this a out of the box and mount them or no?

 

SJW,

what exactly is a "sprung-hub disc"

nice write-up!

mike

 

http://www.google.com/search?sourcei...silicone+fluid

I tell you, I am not crazy!

 

Sucks for VW guys...lol