When I bought my mustang approx. 9,000 miles ago (its a 96 Mustang GT w/ 105,000 miles) I noticed that 5 gear wasent engaging smooth, so I changed the tranny oil, but didint fix the problem(this was 6 months ago). I also removed the shifter assembly and greased up the shifter (the bottom of the shifter where it connects to the tranny).About a week ago I noticed that sometimes Reverse would get stuck, and literally I have to hit the shifter to get it back to neutral. Today after work 3 and 4 gear would not engage it was as if something was missalined or something. Is my tranny going out? Should change the oil and put some synthetic oil or something? If it does need to be changed how hard is it? (i'm mechanically inclined I have changed motors, tranny's but on Hondas and Integra's never on a Mustang GT). This sucks there goes my money for my PI heads and Intake, and gears