The cover ahead of the hydraulic unit. You may want to remove the chain from the coupler , slide the back sprocket back and then see if the shaft has movement. It should only have a movement of 1-3 thousands of an inch. If the bearings are loose, the shaft can move ahead uncoupling the teeth on the low range gear from the shifting collar. Remember, gears are not moved as this is a constant mesh transmission. Do you have a parts manual,shop manual? Questions?