Anyone have a dual mass flywheel for sale?

[jay23ls]

Hello, first post on this forum! Got pics of my new-to-me C4 below

Been researching flywheel stuff since my clutch is getting replaced at a shop (couldn't do it myself right now). Some have said I'll def need a new flywheel, others including Jim from Power Torque Systems says no way to tell w/o looking/testing. So I'm starting the search now in case it cant be cleaned/resurfaced/machined etc.

Also, overall more ppl have advised against going single mass than the ones who favor it. Will do it if I cant locate a DMF or the price for one is very high. Jim btw has a new one but much too costly for me right now.

Please let me know if you have one and how many miles were put on it. Thank you!

 

[jay23ls]

She's a 94 LTI 6 speed 94k miles

 

[Hib Halverson]

New dual mass wheels are long-since discontinued by GM. No one in the aftermarket ever offered them.

Good used DM wheels are quite rare.

Faulty DM wheels are common.

Generally dual mass wheels cannot be surfaced by conventional methods, however, there are a few machine shops which can resurface dual-mass wheels and they are usually the guys who resurface the dual mass wheels used in BMWs. Find one of those guys and you may be able to get a DM wheel surfaced.

That said, the secondary mass is also the friction surface for the clutch. When you machine material off that, you decrease it's mass and that degrades its heat sinking ability.

As for putting a standard flywheel in place of a faulty DM wheel, that's what I did on the C4 I owned until just recently. I installed a McLeod aluminum wheel. I had it in the car for 12 years with never a problem. What are the downsides? A modest increase in gear rattle from the transmission. The upsides, the engine rev'ed quicker and had better throttle response.

 

[jay23ls]

New dual mass wheels are long-since discontinued by GM. No one in the aftermarket ever offered them.

Good used DM wheels are quite rare.

Faulty DM wheels are common.

Generally dual mass wheels cannot be surfaced by conventional methods, however, there are a few machine shops which can resurface dual-mass wheels and they are usually the guys who resurface the dual mass wheels used in BMWs. Find one of those guys and you may be able to get a DM wheel surfaced.

That said, the secondary mass is also the friction surface for the clutch. When you machine material off that, you decrease it's mass and that degrades its heat sinking ability.

As for putting a standard flywheel in place of a faulty DM wheel, that's what I did on the C4 I owned until just recently. I installed a McLeod aluminum wheel. I had it in the car for 12 years with never a problem. What are the downsides? A modest increase in gear rattle from the transmission. The upsides, the engine rev'ed quicker and had better throttle response.

Thanks for the info. Shop said the flywheel is ok and they re-surfaced it. They're a reputable shop that have done C4s before so all should be ok. I'll keep the McLeod in mind for the future!

 

[G Winter]

The DM flywheel has bearings and springs in it. There is also some lube in the bearing part and has a seal.I was told the seal on the earlier flywheels was not as good as the later and will leak if debris get to it. This happened to my 90. The clutch was fine when cold but when it got warm would start to slip.What I was told is the lube leaks onto the clutch surface.The seal also can make resurfacing a challenge. These are things I was told but can not verify although the way my clutch acted seems probable.
A sign that the internals of the flywheel are bad is excessive transmission rattle when warm. Mine went out when I could still get a new flywheel, and the rattle went away after installing it .
If you can live with transmission rattle at idle then go with what Hib said.With the cost of replacing a clutch taking a chance on installing a resurfaced flywheel might be like rolling dice.