Having a problem with our dinette slideout. It is a simple Power Gear twin rack and pinion driven by a single motor. The slide room goes out until the flange on the inside of the slide room hits the...
It sounds to me like they may have cut the rack a little short, or installed it slightly too far to the inside.
Probably the solution to fix it "right" is to pull the slide completely out of the camper, and install the correct-length rack, or install the current rack correctly.
The short-cut solution would be to devise some sort of stop to prevent the slide from coming in too far and coming off the rack.