MACHINE OPERATIONS AND CONTROLS 6. Furthermore, if the machine travels in reverse, a gap is formed between the track roller, idler, and rubber shoe. When turning in a condition where the rubber shoe cannot move to the side because of the object it is passing over, or because of some other object. When the rubber shoe has moved out of alignment and the idler or track roller are not aligned with the core. If the machine travels in reverse in this condition, the rubber shoe will come off. If the machine is turned in this condition, the rubber shoe will come off. 133