Judging by his/her screen name, it appears that he/she has a 2003 GT. If that is the case, then it should have the Trak-Lok differential. Or maybe the car has too big of tires and not enough power to spin both of them (I'm assuming you are doing a burn-out or something like that, correct?) like me (stock motor with only exhaust pushing 315 Goodyear's...Only my left rear spins at times, but then sometimes both do:handball: )BlueStreak03 said:If your car was equipped with a Trak-Lok differential, it's in need of a rebuild. If your car has a more typical car differential, then it's perfectly normal. All that's happening is the car's power is being fed to the wheel with less traction.