I just bought an 02 ZL 600 efi esr. I put new slides in the rear skid and replaced a couple bearings and wheels. Now when you run the sled on a stand you get this clicking/ratcheting sound from the track. I removed the skid again and all is well. I cannot see any problems. I also have a friend that put slides in his 02 ZR 600 cc and his does the same thing. Both sets of slides were arctic cat slides. Has anyone else had this noise or problem. Is it normal? When your ride it you can hear the track, but we don't have a whole lot of snow yet so some track noise is expected.