I have the rear axle off the 51 B to replace bearings, seals, gaskets, etc. When I spin the PTO bevel gear to the left I think I am seeing a broken thrust washer flip up on the right side. It appears to be a gray plastic or Fiberglas looking piece. I can't wiggle it out. Is that what I am seeing? I assume I need to replace even though this will be a parade tractor and never any intent to use the PTO. I really didn't want to get any further into the trans since that seems to be a complicated group of parts to pull to get to the washer. The service manual leaves a lot of detail to be desired. Is this a difficult part to get to and get everything set back up correctly?