I've typed out all I've learned about this wiper mechanism a few times before. We wish the wipers were outside the cabin like most other brands. Before 1968 Chrysler had metal bushings everywhere. Those would wear to clanking and/or squeaking behind the dash. Our first 67 went so bad that the cycling circuit breaker inside that switch cycled repeatedly until it failed.
When replacement plastic bushings in a daily driver last only 2 years where OEM lasted 20 plus years we are quick to blame the quality of the replacement bushings.
Because the pivot shafts run in 2 short bronze bushings and move only 180 degrees while pressure from blades is one sided, the wear pattern in those bushings looks like l\l . The drivers side pivot is catching force from the motor and transferring that to the passengers side pivot so most of the wear will be in the drivers side pivot. The good news, Pivot cast housings are mounted with 2 bolts, so symetrical. We can buy pivot service kits with grease fittings. We can mark the housings with a sharpie, remove them, flush, grease with white lithium, then re install the housings rotated 180 degrees from where they were (marking at bottom moves to top), with new water seals too. This puts whatever amount of wear the steel shaft has to less worn bushing walls. Wipers run smoother, quieter, longer.
If its not a daily driver, rarely driven in the rain, go at it one way or the other to replace bushings alone, and cross your fingers.
