Hi everybody, been working on the problem with the slide, contacted Lippert who were a great resource and spent a lot of time just studying the source of the gear chatter. It's kind of a long post so bear with me.
Here's what I've found, the slide had been taken out of the trailer to repair some water damage before I purchased used it from the dealer. When they reinstalled the slide their service department cocked it by about two inches so one end was off by two inches from the other end.
When the slide was all the way in or out the two inch difference was not noticeable because the slide was either flush or all the way out against the stops. The only time it was noticeable was when the slide out was part way.
This off kilter caused the idler gear packs which are on the frame to bind on the gears when the slide was moving in causing the gear chatter. They were out of sync.
The easiest was I found to check is to measure the gear track or count the teeth on the track from it's outer end to the gear pack. The measurement on my slide was just over a two inch difference.
This two inch racking of the slide not only caused the noise when the slide was moving in it also twisted the metal frame of the slide just a little bit so the entire slide mechanism was a little out of square.
My fix was to re align the slave idler gear (corner away from the actuator) about a half inch past what would be considered the zero setting which compensates for the racking of the slide mechanism and will help move the slide assembly back to square.
I'm expecting that over the next few trips with all the bouncing and torsional twisting the slide and trailer will experience everything will return to close to normal and that last half inch can be adjusted out.
Right now the slide only produces the gear noise occasionally, maybe one time out of 5 retractions which a noticeable improvement.
The noise is annoying but won't cause a fatal failure.
It's a real shame how sloppy the service department repaired this trailer, monkeys with hammers could of done better. Been dealing with leaks, loose seats and benches and all around sloppy work since I brought the Catalina home.