Picked up a Diplomat as a donor machine, broken ring gear and no motor, rusted frame but the rest looked pretty good so as a machine to cannibilise for spare parts I couldn't let it go.
Dismantled the rear rollers and there was plumbing PVC pipe in there.
Closer inspection revealed that the 4 rivets had popped on the roller end and said PVC was cut the exact length to jam it in place off the opposite roller.
Given how difficult it was to get the pulley off I would hazard a guess this was done a very long time ago.
![[Linked Image from i54.tinypic.com]](http://i54.tinypic.com/rssl12.jpg)
![[Linked Image from i55.tinypic.com]](http://i55.tinypic.com/33naw3o.jpg)