How can I tell if my DMF is good or bad with it on the bench?

[Greg Pettit]

Took the trans and flywheel off to repair the oil leak at the back of the engine.

The flywheel looks fine, all the parts are there, etc. The clutch surface is free to move about 3/4" either way with very little resistance.

We took the clutch side of the flywheel off, and found no worn parts, and everything looks good except for a good coating of oil.

Should I be able to move that friction surface as easily as I can by hand?

Thanks for any info,

Greg

 

[6 Nebraska IDIs]

Yes the move very easily, I have two brand new ones and the move with the touch of a finger. But the maximum distance that disc should travel is like an inch and a half or something.

 

[6 Nebraska IDIs]

Actually 1/2" is the max.
Move the disc one way, mark the tooth and disc, then move it the other way and mark the tooth at the point the mark on the disc is at. Measure distance.

 

[Greg Pettit]

Ok, it seems like the measurements are good on the rotation, it just seems strange to see that much undamped freeplay on a flywheel.

I was wondering if this may have been causing the rattle at shutdown I have been hearing.

Greg

 

[towcat]

Ok, it seems like the measurements are good on the rotation, it just seems strange to see that much undamped freeplay on a flywheel.

I was wondering if this may have been causing the rattle at shutdown I have been hearing.

Greg

That's normal for a DMF to have that much play. They're designed that way. So is the rattle on shutdown too. Sounds nasty, but the firing pulses on these motors is pretty abrupt for the start and shutdown of a motor.