[cbreez]

Grinding into reverse is generally one problem and one problem only...incomplete clutch disengagement. The input shaft is still slightly spinning. Doesn't matter what transmission at all. The transmission is probably fine. Reverse is not syncro'd and all forward gears are. That's why the grinding doesn't occur in any forward gear. When you shift into first, third, whatever... you are stopping that rotation, then it will go into reverse just fine. The problem is still there, a lack of complete disengagement of the clutch.