Vibration on 1991 Ford Escort

When I accelerate after 40mph I start to get a very bad vibration.When I deccelerate the viberation stops. I have replaced all motor mounts (4) ,front tires & front end aligned & I still have the vibration when I accelerate.

Asked by for the 1991 Ford Escort
This may be due to a bad axle, or more specifically, a binding inner CV joint. They are hard to diagnose because it's hard to look at it and know if it's bad, but that is what I would look at next.
1 more answer
Depending on the noise,mine was the front spolier was loose.