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Published by cooljess76

There's been plenty of threads, but none as detailed as this one. I'm confident that I have identified the source of our problems and developed a permanent solution.

I "fixed" my window many times before I finally got sick of dealing with it and was on the verge of retrofitting manual windows into my car. Then one day I sat down and thought the whole thing through from the source of the problem to each step of the self destruction process.

I've known people who have taken their cars to the dealers and spent hundreds of dollars to replace regulators and sliders that still give them troubles. As long as your regulator motor still works and the plastic sliders are not broken in half, this repair should be a permanent fix with no replacement parts needed.

Just follow the steps posted in this thread and it shouldn't happen again or atleast for another 10 years if you use the wrong grease.

Normal Operation:
The power window assembly is composed of a motor attached to a "scissor" mechanism known as the window regulator which raises and lowers your window upon actuation. Both of the regulator "arms" have plastic "sliders" attached to them via a "ball & socket" which snaps together and is held on by a steel "C" clip. The sliders are coated in grease and slide back and forth in a metal channel which is located on the bottom of the window. The window itself is held in place by forward and aft bow-shaped vertical guide tracks which have felt-lined rubber inserts to absorb shock and allow smooth motion of the window during operation.

Self Destruction:
The problem is that when the factory grease used to lubricate the window sliders gets old, it turns into a paste-like substance. This causes one of the sliders to bind, which in turn causes the window to go up or down unevenly. Once the window is tilted, The regulator arms will flex causing the metal ball on the regulator arm to pop out of the plastic slider. This is the first snap that you'll hear.

Then when you operate the window again, the window will only be held on by one slider and the metal ball on the detached regulator arm brushes against the slider track and onto the window glass. This is the crunch that you hear next. The window is now off-track which causes the window to twist inward which in turn tweaks the forward or aft vertical track.

Sometimes, the felt-lined rubber guides that fit into the vertical tracks slide down allowing slop in the window and causing uneven resistance on the window during operation.

The Breakdown:
The cold weather contributes to the grease hardening into a pasty substance, this is why it happens more frequently to cars in colder climates. Hence, less Californians and Floridians having window issues. It doesn't mean we're exempt, just prolonged. My car came from Michigan and my window troubles started on day two of my voyage home. It's not so much a bad design as it is a poor choice of grease on BMW's end. It's really embarrassing when it happens to you in a drive-thru

The fix:
If you have side-impact air bags, DISCONNECT YOUR BATTERY and wait approximately 30 minutes before starting this procedure. DO NOT reconnect the battery while the airbag is disconnected as this will trigger an SRS light that requires a special tool to reset. To avoid death, serious injury, or damage to the vehicle, NEVER work in the vicinity of an un-deployed airbag. Only after the airbag is completely removed and placed in a safe location away from you and the vehicle, is it safe to perform work on that part of the vehicle. While my intentions are to save you guys money by fixing your own cars, the last thing I want is for someone to get hurt. Let's stay safe guys, your health isn't worth saving a couple bucks!

Step 1: Remove Interior Door Panel
1a) Pry out the power mirror switch(driver's side) or the blanking plate(passenger's side) and disconnect.

1b) Look inside the hole, locate the torx head screw and remove.

1c) Locate the hole on the bottom of the interior door handle(not the door lever, the actual handle that you grab to close your door). Shine a light up in there and locate the torx screw. It's the same size as the one you removed from behind the mirror switch.

1d) Remove the trim piece around the door lever by sliding it forward and pull inboard.

1e) Start to pry the door panel off at one of the top corners and work your way around the panel prying the clips out of the actual door. There's 10 of these. Some may come unglued from the door panel and remain stuck in the door. Don't worry, I'll address this in the next step.

1f) Unplug the speakers from the back of the door panel.

1g) Lift upward on the door panel and set it aside.

Step 2: Repair Door Panel Clips

2a) If the door panel clips happen to come unglued and remain in the door itself, just pull them out of the door.

2b) Notice that they are numbered. Clip #1 is located by the door lock pin and they go in order around the bottom of the door panel ending with #10 near the mirror.

2c) Look at the factory glue left behind on the door panel. Compare it with the corresponding clip and determine which side of the clip is up by looking at the imprint of the number left by the clip.

2d) Mark where each clip goes on the door panel with a sharpie or permanent marker. I wrote down the number along with an arrow pointing which direction the clip goes. I also put a dot on each corner of the rectangular impression in the glue on the door panel to ensure exact placement.

2e) Remove the old glue using a flathead screwdriver to pry and peel the old glue off. Make sure your marks are still visible to avoid gluing the clips on upside down or in the wrong location. Remember that they have to line up with the holes on the door!

2f) Use a coarse grit sandpaper and roughen the mating surface of the clips and the door panel.

2g) Get some "JB Weld" QUICK DRY from your local autoparts store. It's the only thing that works!!! Nothing else will stick to the door panel.

2h) Mix equal parts bonding agent and hardening agent on a piece of cardboard. Only mix enough to LIBERALLY do one clip at a time as the working time of the JB Weld is very short.

2i) Verify the number on the clip and the direction in which it goes onto the door panel(<---VERY IMPORTANT!)

2j) Apply a liberal amount of JB Weld onto the clip and firmly press it onto its corresponding location on the door panel. Be sure to place it in the exact spot as the rectangular imprint on the old glue that you previously removed.

2k) If you have enough JB Weld left over, mix it up and apply it around the edges of each clip and if possible slightly overlap the flat part of the clip to ensure a nice grip when it hardens.

2L) Wait atleast an hour or two before reinstalling the door panel. The JB Weld will dry as hard as steel and you shouldn't be able to make an impression in it with your fingernail.

Step 3: Remove Insulation/Sound Deadening Foam
Just gently peel it away from the door and place it aside. Be careful not to let the black adhesive putty stick to your interior or clothing.

Step 4: Remove Inner Weather Strip
With the window in the completely lowered position, pry and unclip the metal clips holding the rubber strip along the inner edge of the door. Try not to bend these clips, a tiny flathead screwdriver works well.
Tutorial Tools

By cooljess76 on 01-26-2008, 05:30 AM

Step 5: Disconnect Plastic Sliders
5a) Raise the window approximately 1/4-1/2 way, so that you can access the sliders through the cutouts on the door.

5b) Using a pair of needle-nose pliers, slide and pull off the metal "C" clips that hold the sliders onto the regulator arms.

5c) While holding the base of the window firmly with one hand, pull the regulator arm ball out of the socket on the slider(This may require some force and perhaps a tool such as a screwdriver or wrench to pry it apart).

5d) Be sure to support the window to prevent it from falling into the door or smashing your fingers. Once the sliders are unclipped, gently pull the regulator arms inward and slide the sliders out of the way.

Step 6: Remove Window
Tilt the window forward and lift it out of the of the door from the outside.

Step 7: Clean Sliders and Slider Channel
7a) Wipe all of the old tacky grease off of the sliders and channel located on the bottom of the window with a rag. Try to get ALL of it out out the crevices using the corner or edge of the rag.

7b) Apply a liberal amount of fresh grease to the sliders and slider channel(I used brown bearing grease which seems to be working fine for me, perhaps there's something better).

Step 8: Straighten the Regulator Arms
8a) Look down into the door through the gap along the top of the door at the regulator arms. You may want to raise the arms by operating the window switch, so you can get a better look.

8b) Check to see if the regulator arms are parallel with eachother(one should not be further inward or outward than the other). Both regulator arms should be SLIGHTLY curved outboard as to spring towards the sliders with a LITTLE tension. If the regulator arms are straight and parallel but are not slightly bent, don't worry, as long as they aren't actually pulling away from the sliders. Adjust as necessary by grabbing the arms with your hand and pulling inward or pushing outward until they are positioned correctly and parallel with eachother. Check again by looking down from the top of the door through the window gap.

8c) Look down from the top of the door through the window gap again and ensure that the balls on the ends of the regulator arms are parallel with eachother(you don't want them to be pointing towards or away from eachother, they should both be aimed straight outboard and parallel). If the balls are not parallel, the ends of the regulator arms are twisted and need to be straightened. Using a pair of channel-lock pliers, grip the end of the regulator arm and gently tweak it until it's straight. This might take a couple tries. Recheck your work by looking down through the window gap.

Step 9: Glue Rubber Guides Into Vertical Tracks
The vertical tracks are located in the forward and aft parts of the door. They are bow-shaped and made of flimsy sheet metal. They house the rubber guides that hold the window in place and guide the window up and down.

The felt-lined rubber guides tend to slip down the vertical tracks over time and in some cases they come completely out. Usually it's just the rear one that slips, so you might not have to mess with the forward one as it's kinda hard to access. This can result in a noisy glass crashing sound when you slam your door if the window is partially or completely down, a loose or rattling window, and it can even cause your window to bind and come off track.

9a) To fix this, simply pull the rubber guide out of the vertical track or locate it in the bottom of your door if it has completely slipped out.

9b) Run a strip of glue down the back of the rubber. Try not to get any glue on the felt inside of the guide(I used "Shoe Goo" since I had some handy, it dries rubbery and bonds to metal and rubber well).

9c) Note that one side of the rubber guide is wider than the other. Prior to re-fitting, look at the metal part of the vertical track and determine which side is wider(inboard or outboard) and install rubber guide accordingly.

9d) Press the rubber guide back into the vertical track, careful not to get glue all over yourself. This can be tricky and may require you to wiggle it into place. Be sure the rubber guide is positioned all the way to the top of the vertical track.

9e) Wipe any glue off of your hands and then run your fingers up and down the inner felt crease to ensure that the rubber guide is properly seated inside of the vertical track.

Step 10: "Tweaking" Vertical Tracks
This is probably the most important step in actually fixing the problem. It's also probably the most commonly forgotten or overlooked step. When the window comes out of the track, it twists. This causes one or both of the vertical tracks to also twist. While your repair may seem victorious, rest assured that if you skip this step you'll most certainly have troubles again later down the road!

10a) To figure out which vertical track needs to be tweaked, place the window back into the guides. Remember to tilt the window forward and install it from the exterior of the door. Line it up into the front track and slowly lower the rear of the window into the aft track while using your other hand to guide it into place from underneath. Once the window is lined up inside of both tracks, slowly and EVENLY lower the window about HALFWAY.

10b) Insert both sliders into the channel on the bottom of the window. Align the sliders with the balls on the regulator arms(you might have to operate the window switch to raise or lower the regulator arms).

10c) Press the balls into the sockets on the sliders until you feel them snap into place(Don't bother replacing the metal "C" clips yet, you might need to remove the window again shortly).

10d) Raise and lower the window a few times to check operation.

10e) THIS IS THE IMPORTANT PART!!! Lower the window completely. With the window completely down, slam the door. Open the door then reach inside and feel the window where it sits in the vertical tracks. If it's still seated in the vertical tracks, raise and lower it a few more times and slam the door again even harder. Be sure to do this with the window DOWN. Repeat about a dozen or so times and if the window remains in the tracks, continue to step 11.

10f) HOWEVER, if the window pops out of it's track after you slam the door, YOU NEED TO "TWEAK" THE VERTICAL TRACK. Remove the window again. Reach into the door and grab the vertical track with your hand. GENTLY twist the vertical track that the window popped out of.

If the FORWARD part of the window popped out INWARD, twist the FORWARD vertical track CLOCKWISE(if it's the driver's side door) or COUNTER-CLOCKWISE(if it's the passenger's side door). It will be the opposite for UK members and any other members who have right-hand drive vehicles.

If the FORWARD part of the window popped out OUTWARD, twist the FORWARD vertical track COUNTER-CLOCKWISE(if it's the driver's side door) or CLOCKWISE(if it's the passenger's side door). Remember this is reversed for right-hand drive vehicles.

If the REAR part of the window popped out INWARD, twist the REAR vertical track COUNTER-CLOCKWISE(if it's the driver's side door) or CLOCKWISE(if it's the passenger's side door). Remember this is reversed for right-hand drive vehicles.

If the REAR part of the window popped out OUTWARD, twist the REAR vertical track CLOCKWISE(if it's the driver's side door) or COUNTER-CLOCKWISE(if it's the passenger's side door). Remember this is reversed for right-hand drive vehicles.

This can be aggravating, but you'll have to repeat this process until you get it right. If the window pops out on the bottom of the vertical track, you can simply roll the window up and then twist the bottom of the track. It it pops out on the top of the vertical track, then you'll have to remove the window again before you can twist the top of the vertical track.
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By cooljess76 on 01-26-2008, 05:31 AM

STEP 11: Put Everything Back Together
Remember to install the metal "C" clips on the sliders before you install the insulation/sound deadening foam and door panel.

Before you put everything back together, be sure to check your work by operating the window up and down about a dozen times. The final test will be to lower the window completely and slam the door. Raise the window back up, lower it and slam the door again. Repeat the process a few times and if the window stays on track, your problem is fixed permanently.

For an excellent set of instructions on removal and replacement of the window regulator assembly Click Here Thanks Coop540iT
Last edited by cooljess76; 04-22-2010 at 05:48 PM..
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By mohaughn on 01-26-2008, 05:43 AM

Great writeup. I just had to lubricate a window on my 328 the other day. it was tilted, but hadn't broke the clips or the regulator yet. Popped of the back slider. Got it level, cleaned/lubricated the tracks, put it all back together. Pretty much exactly as detailed above...

My only comment is that at some point the regulator arms are so badly twisted that you will need a new regulator. Of course, after it pops off the 2nd time I'm usually done with it and don't want to open the door up again for a long time.
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By Marv17 on 01-26-2008, 05:54 AM

wow jesse. thats a lot of writing. but its a great write up. i dont have a problem with the window coming off track or anything, but it sometimes goes down by itself when i push the switch to make it go up. any idea why it does that bro? i havent heard any sounds or what not. pm me what you think it can be.
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By cooljess76 on 01-26-2008, 07:07 AM

Thanks guys, hope it helps someone in the future since this is a common problem with our cars. I'll add detailed pics later.

Marv, I think your window goes down when you hit the up button because the window motor has a "pinch" circuit, meaning that if the motor senses too much resistance, it thinks that something is caught in the window and as a safety precaution it rolls down. This could be caused by a number of things, dirty tracks, that rubber guide might have slid down causing it to almost bind, but not quite enough to pop the regulator arm out of the slider. If it gets worse, I'll take a look at it for you.
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By b.u.ti-ful on 01-26-2008, 03:24 PM

Cooljess. You have proven yourself to be well spoken, intellegent, and wise.

Even without pictures, it is a comprehensive seminar.

When the weather gets warmer I will have another go using a couple things you mention that I did not do.

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By BMW95318TI on 01-26-2008, 04:03 PM

CoolJess, brilliant DIY!! I just had this happen to me last night and I am waiting for the sliders from Bav Auto to get here. I will use this article this week when I do it. Thanks so much. Cheers!
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By DocDuvi on 01-27-2008, 12:26 AM

Just did mine works great!
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By 1996 328ti on 01-27-2008, 01:49 AM

Maybe a link to Chris' photos at
http://www.understeer.com/window.shtml would help.
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By drrty byl on 02-07-2008, 05:12 AM

Excellent article: all the information a new ti owner needs to repair the problem correctly the first time. I followed a similar "comprehensive fix" about 6 months ago and haven't had any problems since.
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By aceyx on 02-07-2008, 05:54 AM

I paid for the dealer to do this once. Each time, it would fail within the 1 year warranty period. After dealing with that three times, I decided to do it on my own. It has been doing well for the past year and a half.

Two additions I might add to this are to grease the tracks using a teflon lubricant ($6, Lowe's) instead of grease. Also, replace the rubber parts that "wipe" the window when it goes down. Clean your window often, as the dirt buildup on the wipers causes drag.
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By robcarync on 02-13-2008, 07:15 PM

excellent write up...i need to do this ASAP...but i have also 'fixed' my windows at least 6 times now...

i always suspected that 'sticky' grease played a role in the failure of these things...sooo annoying!

i have just left the window up for a while since it has been cold weather but i think next time i make it home from SC I may have to tackle this project!
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By woh on 02-18-2008, 10:20 PM

Yes, great write up. Made doing my window easier. I used the slow curing JB Weld. Works well.

As preventitive maintenance I'm now doing the other window that has not yet popped. But, one of the black clip extentions is missing. #VL9. Anyone know where I can get one of these? Others are having the same problem finding these:
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By drrty byl on 02-18-2008, 10:43 PM

Originally Posted by woh View Post
But, one of the black clip extentions is missing. #VL9. Anyone know where I can get one of these? Others are having the same problem finding these:
I hunted for these a while back and never found them. Every catalog I called said I would need to purchase the entire door panel. Let us know if you find a source. I'm guessing your best bet for finding them would be take them off of a panel at a junkyard.
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