My 81 GSL RX-7 starts to get a bad vibration when I go 60 MPH or faster. after I hit about 75 it tends to go away. I Just replaced teh U-Joints on the drive shaft and that did not help any. Does anybody have any Ideas on what it could be?

 

bad tire flat spots? bad alignment? i'd check these before you go throwing $$$ at it.

 

tire balancing, and align should do the trick, i have the same problem when i go over 80... but my tires are bald, and im broke, so i get to live with it

 

are your tires balanced?

 

same problem, had front end aligned, helped a little, replaced the tires that had warped from the out of alignment, and now no vibrations, thought i had a out of balance drive shaft....or worn tie rod......but it was the tires that did the trick......

 

I am pretty sure it is not the tires becuase I had this same problem before I put my new ones on my car last fall. Is there anything that I could test or check that could be causing the problem?

Thanks for the help!

 

do u have any free play when tugging on the tire while its off the ground, indicates a bad tie rod,,or ball joint.or just a loose wheel nut that holds the rotor on,,,(had that happen on the Z)

 

Relocate your tires on the car and see if the vibration moves. That should rule out the tires if they are bad. Mine did it around 50mph then went away at 60+ turned out a rim was bent noticed it when they were being balanced. So life goes on.. LOL

 

Since my tires were bald, I replaced them. Prior to replacement, the car would vibrate so much that I didn't feel safe going over 80mph. Now, with the new tires (Yokohama's) I can go over 100 and it's smooth.