Originally Posted by herk7769
The grinding noise could be the gear and rack mechanism slipping like it is supposed to when at "end of travel" to avoid burning up the motor.
If the slides have been closed for a long time the seals could be stuck to the walls. The motor torque is just turning the gears and not moving the slide.
Try getting a plastic cake spatula and "carefully" run it arund the slide to try and break the seal loose without tearing it.
Then try the motor again.
we had this same issue with our slide. the main cause was not having a slide topper. we thought we could get by without one but we camp in wooded campgrounds and the result was sap/residue gluing the slide to the side of the trailer.
since we had a slide topper installed, we've never had this problem again.