92SE Auto

Just had my mechanic put in a used tranny from the salvage yard.........
whenever I come to a full stop or waiting for the light to change she shifts to neutral then into gear on her own constantly, in reverse she goes into gear then into neutral........very annoying. Sensor maybe? Any ideas on the culprit?

 

have the mechanic fix it right this time...

 

I had a friend with a 96 maxima on auto did the same problem also on speeds when he would floor it sometimes it would just shift in neutral. he took it to a mechanic he said it was slipping

 

From what it sounds like it could be a TCL Solenoid or lack of fluid.