I installed the LMC 6v/12v wiper a little while ago and had to make one of the arms adjustable. The problem was probably "me." I opened the case and this motor has a big plastic gear. I think others are all metal. I've had no problems with it.

For the previous post and a link to a picture, check:
Previous post on the 6v/12v LMC wiper motor


1948 3/4-Ton 5-Window Flatbed Chevrolet

34 Years. Now with a '61 261, 848 head, Rochester Monojet carb, SM420 4-speed, 4.10 rear, dual reservoir MC, Bendix up front, 235/85R16 tires, 12-volt w/alternator, electric wipers and a modern radio in the glove box.