1989 mustang gt aod. I just replaced the tranny filter and fluid is fine. I was hoping it would fix the delayed reverse and 1st gear. But it still seems like It slips in reverse. takes a few seconds to engage reverse and if i give it too much gas it almost feels like it hops. after I wait it while it goes fine. I'm guessing the previous owner had a little too much fun with the car and stretched the band for reverse and 1st gear. Can it be adjusted (with out tearing apart the tranny) or do I need a new transmission?