Wiper motor attachment to linkage

I can't imagine the nut that bolts the pitman arm to the shaft has failed. It's the connecting plastic bushings that fail. There are 4 of them under there and they are a chore to get to replace.
So here are the common scenarios...
A) Work through the radio/climate control area, middle of dash, to replace the one failed bushing. A short time later another bushing fails. One on same linkage that drives left pivot? One of the two that drive the right wiper pivot? Is it the one at the right pivot or the one over at the left pivot?
Regardless, You do have a recurring problem.
B) Package of 4 bushing suggest to go all in, remove inst' panel, etc... and replace all 4 bushings at the same time. Should be good for another 40 years right? Sorry, Odds are in 3 years or less another bushing fails. Then we find a few "rant" threads about the quality of the aftermarket replacement bushings. "OEM lasted 40 years but aftermarket lasted 2 years."
The root problem is increased resistance in the wiper pivots.
C) Purchase aftermarket bushings and wiper pivot renew kits. Install those zerk fittings and grease the pivot assemblies. To mark the pivot before removing so to reinstall rotated 180 degrees is a good move also. End result is nearly total renew. You didn't get new bronze bushings inside the pivots but did get onto a less worn bushing wall. This is the only way to get quiet operating wipers that could run trouble free for another 40 years.
A little F.Y.I. These old Chryslers and one or two others are the only mfgrs that ever had replaceable wiper linkage bushings. If it were most anything thing else, all you could purchase is the complete pivot and linkage assembly.
I know all this because I have played the fool or better said "Let my old mopar make a fool of me". Sat here about 10 years and watched others do the same. I did finally get "other brand wise" and ended my recurring wiper problems.
Replacing a bushing might have been a practical service/repair many years ago. It doesn't pan out for all of us today. Good luck anyway you go.