I am wanting to replace My DMF flywheel and clutch with a single mass flywheel and clutch. Does anyone know what applications will fit the 95's . I have been looking for days with unsure results. Thanks

 

Spec makes an aluminum and steel flywheel as well as sprung hub clutch disks. You can also get a steel flywheel and clutch with a sprung hub from Carolina Clutch.

If you decide to buy a Spec aluminum I have one for sale with less than 3k miles in excellent condition with original machine marks from spec and essentially no wear. I was asking $250 plus shipping. New it was $425 shipped.

 

For awhile I ran a single mass flywheel, then I went back to the DMF.

All I did was get a flywheel for a '95 Z28 Camaro (cheap and good availability) - then I flycut it down to match the surface height of the DMF. I don't remember for sure, but I think that I flycut the Camaro flywheel .120" off the face. Just bring your DMF to the machinist along with the new flywheel and tell him that you need the same clutch surface distance from the crankshaft seating surface - in other words from the inside surface where the flywheel mates to the crankshaft. Easy stuff.

Somewhere I even still have the SMF.

Thomas

 

Thanks Guys. I am still trying to figure out what to put in. I know I would want steel so that leaves the spec out. I stopped at car quest today and they assured Me that a DMF is available through them but one is to the tune of 850 and the other is 1200. I will keep this info in mind. Skip

 

What is your performance criteria and intended useage? if you will be mostly driving on the street my choice would be the DMF. The ZF was originally designed as a truck transmission - the clanking of the gears on mine at idle with the SM was unfriggenbelievable. If you have a stock cam smooth idle engine it won't be so bad - but put in a cam etc. and then it will sound like it is falling apart at idle. I was constantly being asked by passengers and pedestrians if my car was broken. I decided that saving maybe a tenth at the drags just wasn't worth the marbles in a can sound effects.

Thomas

 

I am going SMF this summer at somepoint. Not because I so much want to save the cash on the DMF, but its going to happen sooner or later it seems, not to mention it seem more of a noise issue and not a performance thing. Might be a bit different for me as my car is crazy loud now anyway I am past the point of caring and almost enjoy how unrefined it now sounds.

 

I've heard so many different opinions on how bad this gear noise is with a single mass flywheel. Is this an exaggeration or is it literally that bad? The issue with the DMF is the cost, like stated above. What do the Camaro's flywheels cost?

 

I am a street driver. Sadly I am on a fixed income so I really dont have enough money right now to throw at a dmf. So I am afraid I will have to go smf with a sprung hub disc. Thanks Guys for Your input. Skip

 

Have the Spec 3+ clutch and Camaro LT1 flywheel in my 396. Noise is not really an issue, almost like stock DMF except in neutral and then its not bad.

Cut the flywheel and get the whole set up balanced and installed correctly and raise your idle to 950+RPM. With the discount at GM it was $220 for the flywheel a few years ago.

The SMF Camaro flywheel weighs about 18LBS less than the DMF.

 

RC, yes, many opinions on the sound with a SMF. I wouldn't especially describe it as "loud", but it is an ugly clanking sound (gear slap in the ZF, just pull up next to a semi truck and you can often hear the same sound) at idle in neutral with your foot off the clutch pedal that is worse if you have a performance cam. Keeping your clutch pedal depressed at idle quiets it right up, so does raising your idle speed. Too many times I would find myself stuck in non-moving traffic and not wanting to keep the clutch pedal down - that was when non-gearhead passengers would ask if something was broken, or when people would start rolling their windows down to tell me my car needed a mechanic. If you have loud exhaust you might not notice it so much.

Thomas

 

Thanks again Thomas,
I ended up going with the smf and clutch from CC. I tried to find a dmf but of the 30 or so places I contacted 30 or so said the dmf has been discontinued. I am going to tear the ZF down and see if I can shim it up a bit. I got this info from the zf doc. I had a whine in neutral with the clutch out so I guess if nothing else I have hopes to stop that. I will let everyone know the end result when I get it done. Thanks Skip

 

Got My corvette done and as promised here are My results. When I started My clutch job I had 2 irratating noises. When My dual mass went out it was making a terrible sound that I thought was My transmission going out and if I put it in neutral and let the clutch out at a drive up window it made a fairly loud whining sound. With a clutch kit from Carolina clutch with a stage 2 clutch and shimming up of the gears in the ZF trans, Both noises are gone. Putting shims or spacers in the trans is fairly easy. I got most of My trans parts from the ZF Doc. Good guy to deal with. Parts are the hardest to find for this trans. The only noise I had is when the engine was hot and I shifted or loaded it down it made an unbelievable spark knock. The reason for this was that the steel flywheels that Carolina clutch sells are somewhat lighter than the original DMF. The result is that with out the mass the engine does not have the inertia that it used to have. It was an easy fix tho, All I did was changed to premium fuel instead of the regular I used to run. So know My car shifts better and makes no noise. I would recommend this to anyone that is in the same boat that I was since no DMFs' are available.

 

I read your post above and you said you had 2 noises, one was the whine when the clutch was engaged and in neutral. What was the other? I have just turned 80k on my car and since I have owned it has had the whine and at first I figured the clutch or pilot bearing was shot...but the whine has not gotten worse and since replacing the trans fluid and the clutch fluid my shifting is smooth as silk and the clutch, although weird feeling to me at first seems pretty natural, Im starting to get used to the hydraulics of it compared to other mechanical clutches I have driven.

The whine in N doesn't bother me anymore and I have noticed that the other C4's I have been around with a ZF have this same whine in them. One dude had a car with 24k miles on it and it had a whine in N louder than mine.....

Did you replace your clutch because it whined in N? what was the other sound you were hearing? Did the clutch slip or did it simply engage very high in the action?

Im not exactly sure about your statement above.....what "inertia" are speaking of? And how exactly did changing to higher octane fix this issue? Are you running an LT4 that is 10:1 compression, doubtful since you are in a 95? Are you saying you are now using 91-93 instead of 87 and this makes up for the higher rpm at idle most SMF need?

Last but not least, the SMF I heard on a 92 vette at a show sounds like crap, basically sounded like it was in need of a mechanic.

 

thanks for some real info. I'm in the process of installing a billet steel flywheel from SPEC (approximately 21, 22 lbs) and a Spec stage 3 plus pressure plate and disc. hope mine works out as well as yours

 

Skip
Would you Please tell us the details of the Shims your talking about that eliminates the rattle in your ZF when using a SMF.
Thanx
Dennis

 

I guess I wasnt too plain in My description. The whine in neutral that I had since I bought My vette. It was embarrasing when I would go through a drive up resturant and when I would wait too long and put it in neutral with the clutch out.This was solved By taking the end play out of the countergear shaft. Since My explanations arent real great if You go to bill Bourdains site, zfdoc.com it tells You about the whine. I solved Mine by putting a shim that was .005 larger than the one I had in it. Now the noise after I replaced everything. The flywheel I put in was a steel billet one from Carolina Clutch. It weighs about 15 pounds less than the original. This effects mass or inertia. In short, When I take off I have to rev the engine a bit when I take off. With the original one I could let out the clutch at an idle and it would start moving. The problem with a lighter flywheel is the engine has to work harder to get the car moving instead of the flywheels weight helping out. The plus side is if You have a heavy foot the engine gains rpms' a lot faster. It was more of a case of getting used to it than anything else. Now the second noise. When My car heated up and I was first taking off I had a loud marbles in a can noise. I realized it was spark knock or preignition. You can solve preignition 2 ways. By retarding the timing or running a higher octane fuel. I chose premium 93 octane fuel and now the marbles in a can are gone. Well worth a few bucks at the pump.
Now the noises others have had when putting in a smf. I read that if You put an aluminum flywheel in, the noise in the transmission is amplified, Hence the reason I put steel in Mine. Maybe they hadn't taken the lash out of the transmission and a little noise there was amplified and it sounds bad.
I also went with the castrol full synthetic 10w60 engine oil and I replaced My tail shaft bushing that had slop in it. The result is a completely quiet drive line that sounds like any other stick shift car.
If anyone is doing there transmission and clutch I recommend You talk to the zfdoc. He is a wonderful wrath of information and probably the cheapest place to get the parts You need.
The most ideal application would be to have a steel bilet flywheel the same weight as the original but I had no luck finding one. I was told You could machine a Camaro flywheel down but I havent any access to a machine shop I decided against this. Any other questions for Me just fire away.

 

Dirt cheap I replaced My clutch and flywheel because I started getting a vibration at about 60 and when I stopped and idled it sounded like gears banging. I have a slightly rough idle and when engine the engine loped a bit it sounded like it was trying to lock up. Sounded terrible. When I tore it down I had a lot of play in the DMF. Which surprised Me since My car has 50k on it and I drive it like a Baby.

 

Mtwoolford the flywheel that come with the Carolina clutch kit is the SpecSC05S. So if that is what You got it works good for Me. So You should be happy

 

How difficult was it to add a shim to the counter shaft ?

Thanx Skip

 

Cajun it is super easy. The is a plug on the front of the transmission case that is black and about 2 inches in diameter. You will have to replace this plug when going back together. When You get it out You will see a large snap ring and if You take it out the shim right there. Before You take the snap ring out set the transmission with the tail shaft down. tap on the end of the countergear shaft with a brass hammer or drift. When You do this You can slip a feeler gauge between the snap ring and the shim. Whatever size feeler gauge You can get in it is approximately what clearance You have. If You then pull the front snap ring and spacer out and mike the shim. If You could get a .005 feeler gauge in then You add .005 to Your shim and that is the size You would order. Again zf doc will advise You of what size to put in . He is the best place to order the parts from.