I'm not familiar with your slide setup, but would imagine that motors being out of sync would most likely result in binding. If you can find out which slide system your dealing with, Hopefully you'll be able to find the motor syncing procedure. Sorry I can't be of more help, but I wish you luck with your problem.
I remember my large slide used to struggle on the original 2 - 12volt batteries. Changed to 4- 6volts and no trouble since.
2017 ORV Glacier Peak F26 RLS
04 Dodge 3500 CC, DRW, 4.11 gears, 4X4, Cummins 5.9, NV5600 manual trans.