Just had a similar incident on my 08 Thunder. Both of the wiper blades had always been misaligned, coming down too far on the windshield and over the gasket. I was at Smokey Mountain Coach Works in Sevierville earlier this month having a new sat. dish installed and asked if he could adjust them for me, which he did. I am on my way to Ottawa to join the BAC Maritime rally, ran into some rain today for the first time since the adjustment and after several wipes, the drivers side suddenly stuck next to the mirror. Fortunately it stopped raining soon after and when I got into the park I was going to stay at, I removed the arm to find it stripped. I suspect the other arm will be doing the same. If I understand the fix correctly, with the wiper are off, you place a star washer over the splined shaft coming thru the firewall, bend the "star" sections against the shaft then replace the arm and reinstall the flat washer and locknut. Can I assume that the "star" sections are bent toward the coach and how far back on the spine does the washer fit? Any clarification or other suggestions would be appreciated.