The stock 2016 through 2021 upper arm have glass filled nylon bushings pressed into the upper arm and then these bushings ride on a hardened steel collar with the attaching bolt passing through the center of the long collar. These bushings and the collar were worn out on the left side, I had about 1/4 inch of slop between the collar and the bushing.
Our PIONEER 1000-5D is a 2016 and it appeared to me that these were never greased when they were installed from the factory. Funny thing is that the through bolt was smothered in grease. So they put the grease on the through bolt amd inside the collar, NOT on the outside of the collar and bushings; where the grease would have done some good.
My unit has almost 8000 miles on it. After refinishing the shaft, I made some DELRIN bushings and added a grease fitting to each upper arm so I can give them an occasional shot of grease without dis assembly.. This fixed my "pop".
