I have a 2000 Mustang GT w/ manual tranny. When I shift into reverse, sometimes the shifter won't go completely into the reverse gear and it grinds really bad when I try to back up. Other times it goes into gear perfectly. Ive also read that if you go into 1st gear then directly into reverse it sometimes works. I tried, it didnt work. 1 more thing, sometimes when downshifting from 5th to 4th my gears grind for a second, but the gear is still engaged.