Vibration During acceleration

[95redTA]

I have a 1995 Pontiac Trans am LT1 with the automatic transmission no performance mode button.


When accelerating I have a bad vibration from 40 to like 60 mph anyone got any ideas i'm thinking maybee motor/transmission mounts. It doesn't do it if I accelerate hard or if i accellerate really softly, only if i use a medium accelration.

also trans fluid is where it should be


Also i have a oil leak it seems to be from the front and the back parts of the motor and when the car is at temp sometimes i will get smoke from the back of the engine because of it buring the oil I guess any ideas on that

[blindeyed]

Could be a bad U-Joint. Check both ends of your driveshaft to see if they're still secure. Also, it might be your tranny mounts going bad. Try getting a crow bar up beside your tranny and see if you can wiggle it back and forth. If you see your tranny moving, then your mounts are bad.

[FormulaLT1]

Generally vibration like that is caused by the steel unbalanced driveshaft in LT1's. There was a GM service bulletin issued in regard to it and it is very commen. A easy fix is to replace the steel unbalanced driveshaft with a Aluminum balanced driveshaft like the one's used on the LS1, a side bonus of doing this is added power to the ground cause of the aluminum shaft weighing 1/4+ less. If you need one of these let me know as I have supplied many other members with them. Also a commen vibration problem can be caused by damaged mounts but since most times that type of vibration would be felt stronger at take off than highway speeds, also U-joints would cause a clunking as you started off then as speed increased would become less noisy and produce less vibrations. Good luck to ya.

John

[Matt365]

might also be a bad torque converter.

[95redTA]

Well mounts were fine, talked to a guy that works at a transmission shop and he said from how I explained it, it's most likely the torque converter

also said it'd be about 400-500 to replace including labor, is that a good price?

[FormulaLT1]

That sounds like a good price to,

[Matt365]

yea, thats a good price. I recently had the converter and other things replaced in my transmission. Believed a new torque converter cost, here it is, cost me jus under 300 dollars just for the part. And the installation is quite frankly a cold hard bitch. To do it, hes gonna have to take off exhaust, drive shaft, drop the transmission out, then he can get to the converter.