Ok so I wash my car, detail it, take it out for a drive, everythings great. Keep in mind there have been no tranny problems, no problems shifting between gears, no harsh shifts, everything is fine. I have a 99 Trans Am A4. I notice my revs are unusually high and I give it a bit of gas to see what's up and notice it is stuck in second gear. It won't shift from 2nd to 3rd gear. Once I got to 3500 rpm the rear end start shaking really bad. I let off the throttle for a bit and roll down my windows, I hear a squeaking noise, sounds like metal grinding against metal. Any idea or input as to what it is? Maybe a bad sensor or solenoid, but the rear end shouldn't be shaking like that? Well thanks for your time.

~Jeff