[V8] NAC, MB 190E Wiper question

[Tony and Lillie]

So, the inevitable happened. The wiper on my Dad's 91 190E is stopping in various random places on the arc. If you "help" it along, it will continue along it's path. BTW, this is the single blade with the "gearbox" of sorts. I know this has been discussed on the list in the past, anyone have any first hand experience with them? He's in Oklahoma, and i'm in TX, so I can't go out and take it apart, I have to guide him through the process :(

TIA,
Tony Hoffman