Im thinking bad tires.

 

Glad to hear it. I have also been having a similar problem at 55 to 60 mph but its in the steering wheel so im assuming my problem is the tires cus they are going bad but how would you know if its the shocks or ball joints? sorry to steal away from you

 

well the shocks can and will affect the wheel so its possible, if it is a tire with a broken belt or something along that line i would think you could see it if you jacked it up and spun it..

my experience with the shock deal though is it creates a drastic back and fourth almost wobble like vibration, seriously like it gets worse as you accelerate after hitting a big bump or rr tracks etc .. mine was bad but i am sure any number of things could cause the same wobble type vibration..

 

i used to own a big *** jeep. what your experiencing is "death wobble". what mine turned out to be was on the new steering stabilizer shock, they didn't include a bolt cover/sleeve for one end of the shock. that .5 mm gap was the culprit. hit 60 and then it got kinda scary....

 

Well everyone, the grinding came back!!! After I changed the ball joints and new shocks. It drove okay for about a day, then it started again. I had a similar problem with my 1984 oldsmobile delta88 and it was the wheel bearings. So I had my mechanic check them out and they were torn to pieces!!!! Luckily it didnt mess up the rotor so it was a quick cheap fix. Only $26 for new inner and outter ball bearings. Now she drives as smooth as a hot knife through butter! So if anyone has the same issues, dont forget to check the wheel ball bearings.