i have a 94 v6. when ever the car is under load ie foot on gas going over 55mph there is this shaking what feals to be in the rear of the car. when ever i take my foot off the gas going over 55mph the shaking is gone. i have replaced the rear tires thinking they were unbalanced or worn, which they were, i replaced the two part drive shaft with a solid one. and the car still has this shaking over 55..i really need this car to be running, is there anyone out there that has a clue..thanks alo jeff

 

tranny mount maybe?

 

Sounds like you have a misfire really...

 

so you think the car is miss firing..how can i check that...why wouldnt it happen any other time..speeds less then 55mph..why only over 55 mph and under load..that doesnt make any sence to me..

 

If it was a misfire, it would be less noticable @ 55mph and more noticable at lower speeds.

 

so what is the shaking???

 

so anyone else have any other ideas? the car is sitting in the drive way. when i should be driving it....

 

So drive the car then, and keep it under 55! How are your back shocks? Bad shocks can make the rear axle dance around, especially on wash-board roads.

 

if it was rear shocks why would it only do it under a load over 55 mph?

 

Not saying it is shocks, just trying to narrow down the possibilities. Does it happen no matter what road you're on? I was thinking maybe the road you're going 55+ on may not be smooth. Has anything else on the rearend been replaced, such as bearings? It's a little hard to diagnose when you're sitting in your car, and we're sitting on a computer chair, you know.