· Premium Member
When I had new tires put on, they didn't balance mine correctly and the problem didn't show until after it hit between 60 and 70. Perhaps that's the problem?
I remember when I bought my brand new '90 Miata it did the same thing at 65 mph. Ended up installing a rear cross brace, solved the problem when nothing else would. Beginning in '93 they were installed from the factory.I think most if not all challengers have this problem, no matter what model you have. Call Ryan at stack performance, they make a cross member brace that just about eliminates the vibration completely.
1 - Possibility - will check with #4 below..I am not aware of any TSB (Technical Service Bulletin) regarding a vibration problem. If its not warped brake rotors, you should check the following:
1. Insure that your tires are in spec. roundness wise with a dial indicator. (F1s are problematic).
2. Confirm that the small metal clips that the factory uses to hold the rotors on during the assembly line process are all removed from all 4 rotors.
3. Insure that all the lug nuts properly torqued.
4. Get a road force balance (see link below).
Hunter GSP9700 Wheel Vibration Control System
Found it - "Tinnerman Push Nuts" - follow the embedded link - #10 in the first listI am not aware of any TSB (Technical Service Bulletin) regarding a vibration problem.