I rebuilt the entire right drive sytem about 1 year ago. Since then I have had a problem with the rear clutch shaft( for forward drive) rotating over time until the clutch adjustment needs adjusted. this takes place over about a 3-4 month span, not right away, and depending on use. I can adjust the nut all is fine, but then I also need to re-rotate the shaft so the actuating threads and nut match up again. Has anyone else encountered this? Scott