Sometimes, a plastic gear between two metal ones like that is there for a reason. It acts as a mechanical fuse. If something binds, that gear gets destroyed rather than some other, more expensive part. Other times, it is just a poor design.
I would check and make sure that nothing is binding in your slide. Then you'll know that it's the latter.
2020 Cherokee Grey Wolf 18MT
TV: 2014 RAM 1500 5.7 Hemi