I have a 1990 V8 Quattro automatic tranny and all the sudden one day, the gear shifter wouldn't budge. If you turn the engine off you can switch gears and move it down to neutral and start the car, but then again it wont change. I do press the brake peddle all the way down, but it makes no difference, I've also checked the fuses for the 'thingy' that makes it unable to change gears when you dont have the brake on. Any ideas?

 

If I understand you correctly, you can shift through the gears when the engine is not running but once you start the motor you can't shift? Probably one of two things. The "start in gear" inhibitor (solenoid?) is not working properly or you got a major problem with the transmission. If there is too much pressure in one of the hydraulic circuits it will make it very difficult to change gears.

 

I got the problem resolved. I called a buddy who works on these cars and he said what usually causes this is the brake light switch down by the brake peddle. So I spent a couple hours and 7 bucks for the replacement part, but it still didn't work. So I went back to the fuses and saw that one of the fuses was a mini one instead of the regular one, so I replaced it and it works perfect now. Thanks for the help.