I just bought a b4c car and it has a strange vibration around 2500 rpm in each gear. I have pretty much eliminated the driveshaft because when you push in the clutch and let the car idle down at speed the vibration stops. You can feel the vibration through the shifter. The car has 136000mi on it. Could this be a tranny or motor mount?

 

If the car will vibrate in neutral not moving, try removing the belt/belts to see if vibration is from an accessory. If no change I suspect that maybe a problem with the clutch, with that mileage the trans input shaft & or pilot bearing can be worn out & it makes the clutch assm run out-of-round and subsequently out of balance, a torsion spring in the clutch disc can be out of place also. It is a big job to change the clutch, so get a second opinion.

 

I remember when my tranny mount was bad in my C3 you could feel it right through the steering wheel when acelerating hard.

 

Thanks guys, I will try the tranny mount first because I was going to replace it with a poly one anyway, if that does not work I will go from there.

 

Check your bell housing bolts as well.... these can come loose under high torque and cause lots of vibrating issues....

 

Check bellhousing bolts, and if its an automatic check torque converter bolts. I had a vibration in mine right @ 2500 and my bellhousing and torque converter bolts were loose because I hadnt rechecked them after the motor swap...Tightened bolts it all went away.

 

Ditto on the bell housing and TC. Just retightend mine, added some thread-lock and all is well.

Just a few other minor problems.

Jim.