c6_rob

Hello guys,

Recently ive picked up some nasty vibration under hard acceleration Its comes when im pinning 2nd or third gear from 3.5k to redline. I can really feel it in the shifter and the car almost feels like it has light wheel hop.

I inspected the tranny and motor mound with the car on stands but theres no real noticeable signs of damage. I know they could still be bad around the top where i cant really see but do you think this is it?

Again, it happens under hard acceleration only.

c6_rob

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TCW

Clutch slip?

Tom

c6_rob

I was thinking kinda thinking clutch slip. Does clutch slip typically smell? Any ideas on how to differentiate clutch slip from motor mounts etc?

Thanks

TCW

Clutch slip sometimes doesn't smell under hard acceleration if it is just skipping on the pressure plate. (warped pressure plate)

To check for motor mounts, block all 4 wheels then have someone rev the engine and release the clutch SLOWLY. If you have a broken motor mount, the engine will rise up out of the cradle an unusual amount. You'll see right away that the engine is not secure to the frame.

Tom

MarkRx

could be shifter noise, oil sump, or even exhaust rattle. start there first, motor mounts are no fun.

c6_rob

Thanks, I will try this tomorrow

c6_rob

Im pretty sure its not shifter noise or exhaust. Tell me more about the oil sump though.

Thanks

TwinSpin

It could be clutch balance


Jay

c6_rob

Did a lil searching on clutch balance. Sounds possible. Ive got 42K on it and have had no clutch work. Do you think a clutch could just go out of balance like that?

c6_rob

I checked, not the motor mounts or tranny mpunts. Any other bushings back there? Torque tube, half shafts??

c6_rob

OK, not the clutch. I changed the shifter bushings, although it did need em it still does it. Its not the motor mounts. Any other bushings back there? Torque tube, half shafts??

m R g S r

it could be the CV's if its only under acceleration. the CV cups sometimes become pitted and vibrate only under acceleration

an easy way to see if thats the problem without spending any $ is to swap the left and right axles (im pretty sure theyre the same on a c6) because it moves the pitted area to the back side of the cup where the bearings inside the cv don't contact under acceleration.

Robls6

Torque tube rubber couplings?

c6_rob

Thanks for the leads guys. Where are the rubber couplings located? Can I check them with the car on a lift? If its not the bushings im gonna swap the axles.

Ill just go down the list untill i find it!!!

E39M5Speed

any update on this issue?