Original part was worn out. It would not turn.

The original piece is 100% plastic (with metal shields only to prevent burning). The bushing of the arm was badly worn out in one side. The arm was no turning properly or at the end no turning at all. I decide to drill the new part in order to fit a brass bushing inside (1/4" ID, 5/16" OD, about 2" long). I expect it will last considerable longer. I would say this is a typical "defective by design" problem.