Vibration in clutch pedal

[scottewid]

1986 951: When accelerating full throttle and I press the clutch pedal to upshift, I feel a very strong vibration through my foot. It is almost identical to the "buzz" you feel in your hands from some cheapo lawnmowers, you know the kind that makes your hands numb and tingle after holding on for a while.

At more sedate accleration, and even fairly spirited driving, it's non-existent, only happens at all-out acceleration. Also, doesn't happen if I downshift to 4th at say 75mph, accelerate to say 90mph, then I feel it when I upshift back to 5th. It never happens on a downshift.

Clutch feels fine otherwise, no slipping, no noises. Any ideas what this might be and is it a harbinger of a clutch replacement in my near future?

[Lawrence Coppari]

Does it do it in neutral when you just rev the engine with the car not moving?

[mike944]

maybe your throwout bearing.

Mike

[scottewid]

I'll check tonight to see if it does it in neutral after revving and will post results.

If it does or doesn't, what might that indicate?

[scottewid]

P.S., I don't think it's motor mounts because the classic symptoms of vibration at idle that goes away around 1500 isn't there. It's smooth as silk at idle.

[scottewid]

Tested for vibration when revving in neutral then pushing in clutch, and there is a slight bit of it, but not as pronounced as when actually in gear and accelerating.