Okay so heres the deal. My front windshield wiper decided they would just stop the other day in the middle of a complete downpour... aahhhh what luck

Anyway I followed the slow wiper fix diy on audidiy.com and as it turns out my drivers side arm was completely seized i mean i couldnt move this thing with a hammer. So i took everything apart sanded down the inside of the housing and the shafts that fit inside along with cleaning out all the old hardened grease. I cleaned each spline individually with a small screw driver cleaning out all of the rust and dirt built up over the years. After everything was cleaned I very very generously lathered everything in some all purpose grease and reinstalled the motor and assembly. The motor seemed to work fine when I tested it but there were 2 things I noticed that were wrong that could be the source to the problem.

1.) The splines on the in side of the wiper arms themselves are completely shot to hell like pretty much non-exsistant

2.) One of the o-rings just below the splines on the assembly shafts had been broken and the other was too loose after removing it

So I continued on replacing everything and after I reconnected the battery I let the arms go back to resting position without the blades on yet and then put them on. I put the blades on and tested them out they started working like a champ until the drivers side blade gets intertwined with the passengers side and binds up. Only problem is the blades go down (towards the hood of the car before going only about half way up) then they stop in the middle of the windshield which I guess the car thinks is resting position which wont be very safe for me. So I cut my losses and figured id drive with them still not working but randomly when im driving without moving the wiper controls they seem to be readjusting themselves they either go toward the engine or up 2in on the windshield so idk they have a mind of their own it seems like. If anyone has any experience with this please anything will be of use thank you for sticking around this long sorry for such a long post

 

I had this same exact problem. Early last summer i noticed my wipers would scrape slowly across the windshield so I replaced the wipers thinking it was the source of the problem. Then all of a sudden this summer they stopped completely during a downpour (of course); the left arm would get caught in the right arm as if one was moving faster than the other. So I finally took out the wiper linkage/transmission using that DIY and I found that part of the arm was cracked in half... evidently white metal is not the strongest. I also took notice that on the spindles there was not a nut or other piece to hold the wipers onto the spindles. I believe this was the main source of the problem eventually leading to the cracked linkage. I went to my friendly audi shop and got the linkage/transmission system all together for $75, installed it and some nuts to hold down the spindles. I was good to go.

I suggest just trying to find a used transmission system, they should come with the motor too. This would solve any problems u have.

 

Motor and system is fine not gonna spend $75 if everything is working fine I asked a mechanic I know he suggested using a pince(?) punch to make new splines in the wiper arms