A few weeks ago my 93' lesabre wouldn't shift out of 1st unless i played with it. I changed the fuild & filter and everything was fine. That is until the next day when my reverse went out. If i press on the gas hard enough it will jerk back sometimes. trouble codes 31,& 36(neutral safety switch, shift control problem

Did you check and make sure the fluid level is right? Also, you might look for a leak under the car where it was parked.

Robert

yes the fuild level is fine.

A few weeks ago my 93' lesabre wouldn't shift out of 1st unless i played with it. I changed the fuild & filter and everything was fine. That is until the next day when my reverse went out. If i press on the gas hard enough it will jerk back sometimes. trouble codes 31,& 36(neutral safety switch, shift control problem

Sounds electrical. Maybe bad solenoid? Or connection.
I would also try to do a pressure check.