I put slides on in the fall. just got the sled out yesterday. On the snow i found green shavings of plastic from the slide. I looked at both slides, the one is fine the other is carved all the way down in lines. My guess would be a clip that is bad and carving as it passes.? I rotated the track to look for the clip but did not see anything.track looks fine, not crooked, to tight or loose so....I dont know.