My car around 50mph will vibrate slighty while crusing ,but when I step on the gas itget worse untill i hit 65mph or so and stays away untill 80mph and up. The tires are brand new less than 500 miles. Any Help appreciated.

 

Well your probably running way lean if your getting 50 miles per gallon

In any case check your drive shaft-u joints. I had my old drive shaft go back on me.

 

Do you feel it in the shift or the steering wheel?

 

oops not mpg ---- mph minor difference right

 

I feel it in the steering wheel and the seat and so do other people riding with.

 

Check your alignment maybe.

 

It fell like it is comming from the rear also

 

Like I said check your U-joints. My drive shaft would vibrate at different speeds MPH not RPM. Get down there and inspect the joints.

 

Check your diff mounts, your tire balance (often overlooked but a major cause of this is a weight falling off a tire - usually you can get them rebalanced wherever you bought them from for free), and your tires for any uneven wear. If those check OK then you may have a strut going bad, in addition to the things other people have posted here.

 

How do i inspect the u joints??

 

FSM baby... http://www.fc3s.org should hook you right up. Look under How-Tos -> Manual.

 

thanks