When coasting at 25 miles an hour no vibration, but when I apply the gas, it vibrates like crazy, at higher speeds this does not happen, only at the lower speeds,,, 10 through 30,, around there,, when at a stop,, I can rev the engine and no vibration ,, no unusual lifting of the motor,, that would indicate a broke motor mount,

Why would the shaking happen at these certain speeds and only when give it he gas. What should I look for.

93 ford 150 302

Thanks

 

Have you checked ujoints? They can cause vibration you would swear wasn't them. Remember front 1/2 shafts.

 

That's where I would start.