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Window track on BMW e34

At some point the right rear door window track lost the black fuzzy stuff in a few spots. This caused the window to grab the rubber track along the back edge and it got completely smooshed out of shape. The window was still sealed ok but it was a nasty looking mess and only a matter of time before the window would not be able to close. I obtained the $100 part and rolled up my sleeves. (The window track goes around 3 sides of the window, and has extensions that run along the front and rear edges of the door. It is a very complicated piece of rubber)

Procedure

1. Remove the chrome plastic trim strip from the upper inside edge of the door panel. It will snap up just before you think it will break, unless it breaks first in which case it needed replacing.
2. Do not remove the exterior chrome strip because it's not necessary, you will scratch the paint and destroy the $40 trim piece irrevocably. Trust me.
3. Pull back sharply on the top of the inside door panel and it will tip back enough so you can do the rest of the job.
4. Carefully snap off the textured black plastic trim piece covering the vertical support strut between the big window and the small triangular window. There will be 3 screws behind it which must be removed carefully so as not to drop them down inside the door.
5. After dropping the 3 screws down inside the door, carefully unsnap the large textured plastic trim piece that runs around the entire upper perimeter of the door on the inside.
6. Remove the rear rubber window track from the black aluminum channel that you loosened by removing the 3 screws. Then maneuver the aluminum part upward and outward till it's free.
7. Pull the front part of the rubber window track away from it's channel inside the large black aluminum part at the front edge of the door. This will expose 3 more tiny screws which you must remove to get the front aluminum piece out. Now the front most vertical part of the window track can be pulled away from this aluminum piece.
8. Pull the old window track away from the rest of the door frame.
9. Now apply a silicone based rubber dressing to all the parts of the door frame where the new window track will have to be pressed in. You will NEVER succeed without applying lube.
10. Starting from the rearmost edge of the door just at the base of the small triangular window begin pressing the new rubber into place. You will have to push very hard using a tool with a hard but smooth edge. I used a bicycle tire removal tool that had a small spoon shaped end that I could push with without damaging the new part. The 1/4 inch rubber strip that holds the triangle window in will wind up underneath the new window track rubber. You will have to add some lube to this area, and gently pry the 1/4 inch strip up and over the new window track. You can do this last.
11. Next the rear black aluminum channel is slid back down inside the door to mate with the silver colored channel that is inside the door. There is a small tab at the top of the silver channel that you need to catch with the bottom of the black upper channel. Then with the black aluminum channel loosely in place push the new rubber window track inside it. At this point you may have to stretch and reposition the section that you just installed around the rear triangular window until the rubber window track falls in the right place. This is why the lube is so important. Before you install the three little screws from inside the door, make sure the position of the aluminum channel is like the one on the other side of the car.
12. Keep working the new window track into place along the top until you get to the front edge. Now install the front-most vertical rubber track (the one that seals the gap between the front and rear doors) into the large black aluminum channel. You will need lots of lubricant again.
13. Tighten the 3 screws of the black aluminum channel in place. Install the front edge of the rubber window track now by just sliding it into the receiving channel in the black aluminum part.
14. Now roll the window up and down a few times CAREFULLY. If anything is out of place and get jammed, it might be very difficult to reposition correctly. Also shut the door and make sure everything looks right. I had a minor problem at the front most corner where the seal just touches the back edge of the corresponding front door seal. When I first shut the door this piece caught on the bright trim that it sits against and folded back on itself. A little repositioning of the front part of the window track and some lube on the bright trim piece got everything working correctly. If I had left that piece folded over that way for a few days I'm afraid it would have taken a set that way.
15. Now you replace the large textured plastic trim around the door frame making sure that the rubber window track at the top goes UNDER this plastic trim. See the other side for reference. 16. Next comes the vertical textured plastic trim that covers the 3 little screws. The secret to this one is to put the rear (of the car) edge in first and then snap it around the front. Snap the top of the door panel back on, replace the chrome plastic trim strip and you are done.