I know what you mean about the slide. It is pretty big. I inspect ours regularly, keep it clean, lubricated, and make sure the wiring harness isn't being pinched. So far after a year of ownership, it's been flawless. I did however notice that it operated much smoother and faster after it was lubricated, and I've lubricated it 2x this summer.
Regarding the third track, I don't know how much it helps, but it probably doesn't hurt anything. Even though there are now 3 tracks, there is still only 2 motors located at either upper corner of the slide.
Good luck with the repair and please let me know what they find to be the problem. Thanks...
__________________
|