sure ....check it out ....check the lights too .... they have just as much to do with it jumping out of gear .....well , no I musn't tease . Under the center raised section of floor is the selector housing . once you have taken out the floor panels you can get this center panel out .With the engine not running , check that you are fully engaging reverse and the gate is operating properly. If the gearlever moves the reverse selector fully into place ( as far back as first and third ) then the truble is internal . If there is a marble or something jamming the reverse selector then theres your problem . I hope you find a marble !