Originally Posted by SailDJ
I took the cover off, but with the slide closed, I can't reach the motor. I need to find a way to open the slide manually..
That's different than mine. Look for a hole where you can insert a extension socket. There could be a rod in there and if there is, it's designed to accept a socket and turn it manually either with a handle or power drill.
It sounds like the nylon gear stripped out. Not uncommon. Once you get it opened, you can identify. Hopefully you will be able to identify and find the correct gear replacement, I did on mine a few years ago. Entire motor assembly is pretty pricey. Lippert made most of those components.