That's Interesting. Not a motor problem, but the whole passenger side wiper arm broke off my 97 F150 a while back. I'm not talking about just the blade either. The shaft, including the arm that was still bolted to it, broke the phuk in two, and the arm flew off and bounced off the hood of the car next to me while I was sitting at a traffic light. At least their car was a POS and they thought it was funny, so they didn't care about the big scratch it left. I picked up some used parts at the local scrapyard for $20 and fixed it, but I think a wiper arm shaft ought to last basically forever shouldn't it?