I have a 95 LS teg. I had the a similar problem a while back. I replaced the motor mounts put the polyurethane mounts in, and replaced the CV shafts and that fixed it. It was vibrating really bad. Now I noticed it just vibrates some as in the whole car shakes under load. The more load you put it under the more it does it. Its not even as bad as it used to be but Im not sure what it could be now. The CV shafts are no more than 4 months old and same with the mounts. I havent replaced the rear tranny mount yet though.
Any opinons on why it would do this?

 

Re-built/new shafts have been known to be defective. I would check it out. You may have a broken/cracked motor mount as well, you can check the tranny too. You could have warped brake rotors as well, that will cause a godawful vibration. Good luck!!!

 

Check your motor mounts. I've had crapy ones go bad really fast!

also.. make sure u check that rear tranny mount coz thats the one that your motor is torquing against when u get on it.

 

I have the same problem few weeks ago, the car vibrates when I step on the gas pedal and dissappear when I let off the gas pedal. Replaced the axles and the vibration is gone.

 

i put aftermarket axles into my teg and i got the same thing. however, after driving for a while it went away.

 

Alright ill go ahead and try that.
Thanks