Fix that dual-mass!!!

[Hib Halverson]

CAC Members-
The general rule has been that the dual-mass flywheel used C4s with six-speed manuals from 89-96, including all ZR-1s, cannot be machined to fix warpage problems.

I've heard rumors that a few resourceful machinists were turning dual-mass wheels but had never actually seen it done...until today.

Mark DeGroff of "DeGroff Cylinder Head Service and Machine Shop" does all my machine work, except LT5 port work, has been machining BMW, dual-mass flywheels for a couple of years. I was out at his shop, today, doing a photo shoot for one of my web site customers and in walks this driver from a BMW repair shop with rush-rush flywheel resurfacing job. We had to take a break from doing image work to set this flywheel up and machine it. While he cut the BMW wheel Mark told me how he does C4 dual-mass wheels the same way. I observed his process and it works well, giving a dead-nuts accurate surface on the secondary mass.

No more do you have to scrap dual mass wheels which are warped but not too badly.

If you're interested in having a dual-mass flywheel surfaced, contact Mark DeGroff at 818-701-5274 or at mdchs3@verizon.net.

 

[vetteguy]

Thanks for the heads up. I had just read somewhere the other day that they cannot be machined and must be replaced if damaged. I'm glad that is not true. Guy

 

[Chris Kennedy]

Thank you for telling us about this Mr. Halverson!! It's always great when someone dispels a "myth" about parts or repairs.

/s/ Chris Kennedy

 

[LT4man]

Hib,

Thanks so much for this important piece of info regarding our dual mass flywheels.

While surfing the net last year, I had come across someone who also does this work. I ended up losing the page and could not find it even though I kept on searching.

This is phenomenal news!

Thanks so much for sharing this!

SAVE THE WAVE!

 

[G Winter]

The timing on this is great, I think I am very near a clutch replacement.

Glenn

 

[lex luther]

I had this done on my 92. Still have not gotten used the pedal being almost fully out when the clutch engages.

 

[funseeker]

Yes the units can be turned. If you can find someone who will do this with out tearing the rubber between the two disc's. Depending on the number of miles on the fly wheel. I have done 6+ clutches each on a different car(90-95) all around 100-120k.
All of them the amount of play back and forth was 3/4 of an inch or more.
This means the clutch face actually could be moved by hand back and forth on the flywheel. I can't imagine what dropping the clutch at the stop light did.
I have heard yes and no that some play is normal. We always used a single piece centerforce as the replacement. I have not seen a new duel face to know for sure. Can anyone answer this?

 

[David-F]

About 3/4" movement back and forth is about normal there should be some restriction in movement, just keep an eye out for oil if you find oil aroung the flywheel hub you will need to replace it I have only had two with problems over the many years I have been doing this and I have been having the flywheel mechined I think ever since 89 when I did my first and have not had any problems.

David Fulcher