[mgarblik]

For the car that has trouble going into reverse when hot, try this little test. Shut the engine off and try to shift it into reverse or with the engine still running, put it in 1st and then quickly into reverse. If it goes in without much issue in these conditions but not when running and going from neutral to reverse, the problem is a grabbing pilot bearing. Since reverse is not synchronized, the input shaft is still turning when you clutch it instead of stopping and this causes the grind or no shift to reverse.
For the chatter in reverse only, I will have to think about that one for a while.