First of all I'm a hillbilly and will try to fix most anything.

My rear wiper motor stripped the driven (big) gear. Removed from the vehicle, noticed there are no screws holding the case cover on, OK, while they look like rivets but they are actually protrusions of the die cast housing and will break off flush.

Reinstall the cover and drill and tap the housing for 8-32 screws. Be sure to use the cover for a template so everything lines up. The shaft has serrations that deform the plastic gear ID to hold it in place. When it fails it enlarges the bore of the gear. This was my first experience using JB Weld so I had my doubts. Anyway I used a small 3 corner file to create several "keyways" or notches in the plastic gear to give the JB Weld something to flow into. Be sure to prep the shaft and gear with a non-petroleum based solvent. (something that won't attack the plastic)Brake cleaner worked for me.

Clean the housing, check and clean the electrical contacts,the old grease was pretty dried out so I used Lubriplate 105 white grease.(not to excess)
Reinstalled and ran the motor until it reached "park", then re-attached all the linkage. You could or maybe should give it about 24 hrs to set up since the JB cures slowly before reattaching the linkage.

At this point it has performed flawlessly for 2 weeks and saved me about $140.
Yes,I could have tried a P&P but it's 180 miles one way and may have the same issues and we were starting a 2000 mile vacation trip the next day.