I have a 2001 X5 and somehow the gears in the rear wiper assembly got stripped, is there anywhere I can replace just the worn gear?

jut tighten the 13mm nut that holds the wiper on. it is loose anc caused the wiper to fall down. seen it hundreds of times. just remove the plastic cap and it will expose the 13mmm nut.

I tried to tighten that nut, and it didn't change anything, also for some reason my windshield washer pump drained all of my windshield washer fluid around the same time that my wiper stopped working, and now makes a really loud noise, even when the car is off.... The only way to make the noise stop, is to pull the windshield washer pump fuse..... Any suggestions, and is there anyway to get to the gears that control the wiper movement, since I think it would be the gears being stripped.

I was looking around on X5 world Forums, and someone said that when they had it happen to them, they found out that it was a bad IC on the board that controls the wiper arm movement, does anyone know how to get to the assembly so I can determine what is wrong with it I don't want to start taking the interior panels apart ..... I swear X5's always have problems in the winter.