Frankt

I have an 2011A6. The windshield wiper on the driver's side jumped time and actually came off the windshield and on to the side view mirror. This happened during the snow storm we had in NJ on October 29th. Before the wiper came off the windshield, snow was being packed by the wiper blade each time the wiper functioned. As the snow pack increased, the travel of the wiper mechanism changed since it appeared that the mechanism thought the snow pack was the bottom of the stroke. As such, the wiper arm started to travel to a further point on the windshield. Eventually, the wiper arm came completely off the windshield on came to rest on the side view mirror. Thankfully, the passenger side wiper continued to function properly.

When I brough the car in for service, the repair was done very quickly. The nut holding the wiper arm onto the drive mechanism was tightened and the wiper mechanism was re-timed. When I questioned why the nut came lose, no one could answer the question. Needless to say, I am concerned that this will happen again.
Has anyone else ever experienced this problem?

SchwarzS6

My guess is that the wiper glade nut was not fully tightened and the blade slipped on the shaft due to the heavy snow load. The drive shaft for the blade is a slightly conical shaft and the blade arm has a matching conical hole. When you tighten the nut it drives the blade arm cone onto the shaft and if they tighten it enough it should not move. To fix it all they did was loosen the nut, move the arm to the proper position and retighten. I have doe this many times for various reasons and it is pretty quick and simple.

PJRed2008

Could be by design to protect the wiper motor from burning out trying to force the arm into the park position. Would rather have a loose nut than a burned out motor.