Mustang Shake

That is the only way I can describe it as I have had a 94 and 95 that have done the same thing. When I get to about 35 mph the car shakes and then at about 40-45 it will shift to the next gear.

This isn't like a slipping where the engine revs, it just makes the car shake.

Anyone have any idea what would cause this?

I have a feeling that I will have to have it rebuilt. Has anyone done this, any tips? Do you think I could do this myself?

Thanks,

Keith