After installing my motive 4.11s I started a vibration around 85. I also put 33 12.5 20s about 2 weeks before the gears. I didnt really get that fast before the gears. Its a high speed vibration. Could it be my drive shaft? Or tires?

 

Swap the tires front to back and see if the vibration changes. I'd do the simple thing first.

If you feel it in the seat of your pants, it's coming from the rear more than likely, and if you swap them and it changes to the steering wheel or pedals area then it's now on the front.


I mean you could get em rebalanced if needed, but the place will likely just say "meh" as thats well over any speed limit. We tell customers that alot when they complain of shakes over 80 mph.

 

Ive change them around and had them rebalanced twice. Im wonderin if its because they r a federal mud tire or a drive shaft problem. I may see if I can borrow a smaller set of street tires to swap with and see what happens