vibration problem
 

The tires have been balanced and still have an odd vibration that seems to be worst when in 5th around 55/60 mph. It could probably be a number of things but has anyone experience this problem before?

Does it smooth out around 75? mine did i think that it was the idle arm or something. but it wasn't a big problem. later

Have you verified that its a wheel/tire problem as opposed to something else in the driveline?
To do this, take the car out and get it up to the same rpm that the vibration occurs at in 5th, but keep it in another gear, (i.e. 4th), if you dont have the vibration at the new speed, its the tires/suspension, if the car starts vibrating again in 4th, theres something wonky in the driveline.

Hope this helps,
J

could be the universal joints on the driveshaft.

Its can be a number of things:

1. bent rim
2. balance
3. tire wear / bad tires / bald spot / etc
4. drive shaft bent or out of balance
5. u joints
6. suspension parts worn / shocks etc.

most likely, ujoints bad drive shaft needs to be serviced.. get the aluminum drive shaft from summit. 149 bucks.. new joints and is so light weight you'll gain some performance and runs smoother from less centerhung wieight.

thanks for all the response