GS291 slide out

[Thurman]

I knew I would find something to ask about on this forum, so here goes: When I push the switch to open the slide on this GS291, the front end of the slide will move about three inches (3") before the rear end starts to move. IF I go and give the rear of the slide a gentle push, it will move and come in alignment with the front and then the unit will move as it should. Basically the same thing when retracting the slide, the front end moves about 3" before the rear of the slide starts to move. And again, a gentle push from the outside this time aligning the slide and it moves as it should into the closed position. I'm one of those who will tear into most anything and not worry over bolts left over. But not this time. Any advice as to what to look for, what to do about this? Thanks, David