Window Regulator And Motor Replacement DIY.

[tbreihan]

About 18 months ago, my 1993 325is suffered a catastrophic failure of the electronic brain that controls the one-touch window motor for the passenger-side window, resulting in a totally non-functional window. I dealt with it and kept putting it off, but then two weeks ago, the driver's side motor started slipping and then failed altogether, leaving the window down in the door. I decided it was time take care this.

Prior to diving into this, I had read the procedure in the Bentley and few times, and I was concerned about the Bentley's requirement that the windows glass be removed from the door prior to removing the regulator, and the issues of re-aligning the windows that this would entail. However, I consider myself to be an above-average shade tree mechanic, so after psyching myself up for two weeks accumulating all of the parts that I would need to do the job, I felt ready.

Although my window regulators appeared to be fully functional, I understand that, with time and use, their geometry can deform somewhat, putting extra strain on the nylon-bushed pivot of the scissors-arms as well as on the window motor itself. Since replacement of the motor requires the complete removal of the regulator, it seemed prudent to replace the regulators as part of the repair. While the part isn't cheap, it is around one-third the cost of a new motor, and I didn't want to have to perform this repair again anytime in the near future.

A complete parts list for the project is;

(2) Window Motors
(2) Window Regulators
(4) Nylon Sliders
(8) M6X10 hex-head machine screws (4 mm hex-wrench head), nuts, and lock washers
Lithium Grease


Additionally, you will need the following tools;

Ratchet Handle
6-inch socket extension
10 mm socket
4 mm hex head socket
5 mm hex head socket
T-20 Torx head socket
T-30 Torx head socket
Assorted drill bits
Corded electric drill
Dremel tool w/ cut-off wheel discs


Okay, here we go.


Step One: Remove the door panel and vapor barrier:

If you don't know (or have never done this), I would suggest that you stop right here and take the car to your mechanic.


Step Two: Remove the rear window stop:

Lower the window until only about 4-inches of glass are extended beyond the top of the door. You should have a clear view of the bottom of the window and the two extruded aluminum rails that are bonded to the glass, where the little nylon sliders ride. At the outside ends of these rails, you will see odd shaped brackets that appear to be bolted through the glass; these are the window stops.

The rear window stop, the one that is clearly accessible, is the one that needs to be removed. Using the 10 mm socket with the 6-inch extension, remove the top bolt that passes through the glass. The bottom bolt simply presses against the inside of the rail, so loosen it 4-5 turns. Now, slide the stop out of the rail and off the glass. There should be a nylon 'pad' and a threaded brass bushing under the stop; leave this in place.

*** VERY IMPORTANT ***

That large Torx head screw in the window stop with the thread locker on it is the window stop itself. Do not touch that screw unless you want to readjust those window stops later.


Step Three: Removing the window regulator rivets:

*** VERY IMPORTANT ***

Before beginning this, make sure that the window is all of the way up. When you are drilling or knocking rivets out with a drift pin, you don't want the glass to be right behind where you're working, do you?

If your car has bolts instead of rivets, consider yourself lucky; this part was the single most time-consuming step in the whole procedure. It took as long as everything else combined.

The rivets are hard, and if you elect to drill them out, you need to use lots of lubricating oil on the drill bit to prevent overheating and blunting it. Also, when you start getting to point where most of the rivet shank is drilled out, the rivet will usually start to spin. This is problem because, even at this point, you are probably not going to be able to break the head off.

Here's my suggestion for how to get those rivets out; the Dremel! I had to resort to the Dremel even on the rivets that I drilled, so I would forego drilling altogether.

Using the Dremel and cut-off wheel disc, start cutting the head of the rivet up in to as may tiny pieces as you can. Then, using a pliers and large wire snips, start crushing the cut-up head together and breaking the little pieces off. Soon the head will be gone and the shank can just be pushed through the hole.

If you are using this method, you will go through quite a few of those little cut-off discs, so buy a tube full of them. Remember, also, that this is the hardest part of this whole job; once you get those four rivets out, it's all downhill.


Step Four: Removing the window regulator:

Now that the rivets are gone, there are only two things that are standing between you and the removal of the regulator. On of those is a 5 mm hex head bolt near the rear of the door. This is easily removed by reaching into the door with the 5 mm hex head socket on your ratchet handle. The other is the pair of nylon sliders that have the regulator scissor arms clipped into them.

At first, I thought that getting the regulator arms out the nylon sliders would be a piece of cake; just pop off the metal clips and they should pop right out, right? Wrong. Even with the metal clips removed, the arms stayed stubbornly stuck in the sliders. Prying against that aluminum rain that is supported by nothing but a pane of glass seemed unwise, so I decided to try and slide the sliders out the rail with the regulator still attached.

And this is the epiphany that is key to doing this procedure without all of the disassembly that the Bentley specifies. Ready? Okay.

With the rear window stop removed, it is quite easy to slide the rear nylon slider out of the rail. All it takes is a repositioning of the regulator assembly and you can slide the slider backwards, past where the stop used to be, and right out of the rail.

Now, here is the trick. The hinged rail that was secured with the 5 mm hex head bolt? The end of this has to be removed from inside of the door. To do this, you have to keep moving the regulator assembly aft as far as you can, and then the end of the rail will clear the front edge of the hole. Now, slide the whole regulator assembly forward until the rear scissor arm and its nylon slider (which you just slid out of the window rail) clear the rear edge of the hole.

Now, all of the regulator except the forward arm and its slider are out the door. So, just pull the whole thing to aft again and the front slider will pull right out of the back end front window rail. That's it!

Now, this may be a little difficult to visualize, but when you are in the door, it will make sense. Just remember; back, forward, back; this is what makes it possible to remove the regulator by only removing the rear window stop.


Step Five: Preparation:

Reinstall the rear window stop, paying careful attention to the torque of the bolt that passes through the glass. This bolt needs to be little more than finger-tight; over tighten it, and you are looking at buying a new window.

When the stop is on, push the window up as far as it will go. The metal track that is near the latch jamb of the door is the window guide track. Wipe out as much of the old, crusty grease from the track as you can and then liberally lube it up with lithium grease. Push the window up and down a few times and them position the window so that you have clear access to the two extruded aluminum rails that the nylon sliders ride in. Again, wipe as much of the old grease out of these as you can and liberally re-grease them.

Finally, install the new nylon sliders in the rails. These should be oriented the same way as the ones you removed; the open end of the metal clip should face the rear edge of the door.

*** VERY IMPORTANT ***

Leave the metal clips on the sliders. Don't remove them, unless you want to make your life difficult.


Step Six: Regulator Assembly:

Now, this procedure will change somewhat depending on what service you are performing. I am going to assume that we are replacing both the regulators and the motors. Things to remember if you are reusing old parts is to thoroughly clean them and replace any old grease that you remove with new lithium grease.

If you are replacing regulators, the new regulators will likely have a pair of flanges punched through them that act as positioning pins. However, not all years of cars have the corresponding bores on the doorframe to accept these pins. There will be an instruction card attached to the regulator, but it isn't the most clearly conceived set of instructions ever produced.

Basically, if your car doesn't have the holes, the positioning pins need to be cut/ground off. This is another situation where that Dremel tool is invaluable

Now, grease up the gear teeth of the regulator. Don't be shy with the grease.

Remove the window motor retaining screws from the old motor. These are T-30 Torx head screws with a very coarse thread that are self-tapping into the plastic bores on the window motor body.

Attached to the regulator will be a little plastic bag with a pair of circular bushings in it. One of the bushings is metal, the other is plastic. This bushing supports the end of the motor's gear driveshaft in the regulator. It is hard to explain, but if you look at the existing regulator assembly, you will see what I am talking about. You will use one of these, and throw the other away. Which one you use depends on which one you are taking off.

Grease up the motor drive gear and position the new motor on the regulator. In this step, the gear teeth NEED to mesh properly before you can start tightening those screws down. The only way to do this is to put it on there and wiggle it around, adjusting the position of the gear teeth on the regulator as necessary. When it is properly meshed, it will sit in place perfectly on the regulator.

Install the T-30 self-tapping screws. These require a good push for the first half-turn to get them to bite.


Step Seven: Regulator assembly installation:

Installation is the reverse of removal, as they say. Position the regulator on the door (with the window fully up) and install it with the M6X10 machine screws. Use a dab of thread locker on each screw for insurance.

Now, hook up power to the motor and position the regulator arms to where they would be if the window were most of the way down. Push the window down to align the slider rails with the ends of the regulator arms. Push the sliders over to meet the balls on the ends of the arms and then snap the ends of the arms into the clips. When you do this, you should hear a load SNAP as the metal clip engages. A pliers helps to squeeze the arm-ends into the clips. Immediately raise the windows; if one of the arms pops out, it wasn't in there correctly. Try again.

Once everything is secured, put the door back together.

I did both of my doors in about six hours. It took me four hours to do the first door and only two hours to do the second. Much of these timesavings were realized because I didn't attempt to drill out any of the rivets on the second door. Also, I had mastered the regulator removal trick.

This job is a lot easier than the Bentley makes it sound, and it is a good way to save the $250-$300 than most shops will charge in labor. If I had known how easy this was going to be, I would have fixed my passenger side window months ago!

Good luck!

[JedzE36/5]

very nice write up for a problem that will happen to us all eventually. i was hesitant about taking out the glass too but it wasnt as bad as i thought.

[martialartsblac]

Yes good write up indeed. However some pictures would help. Sorry I’m a visual learner. <br>So i spent at lease 10 hours on one window this weekend. And the reg was already removed. It was reinstallation of the reg and the window that kicks my a$$.<br>
Mother of GOD! It would seem when id install it correctly there’s was some kind of electrical failure. And when id install it incorrectly there was mech failure. i.e. arm popping off clip. Finally i get installed for the billionth time and now it only rolls up half way. This after going thru the instructions over and over and reinstalling the motor in various placements on the end and beginning of the motor cycle.<i> { I was lining the reg and the motor correctly as far as the teeth start and stop.}</i> <br> So after this un holy adventure and the final install attempted I went in the house, took a xanax, and had a glass of wine. This morning i get in my car and i go to roll up the passenger window and guess what? It only rolls up half way? WTF. I didn’t even touch that window! Is there some kind of memory reset for the motors? Could this be a comfort relay issue?<br> Please help.
<b> I'm about to go on a tri state killing spree.</b>

[tbreihan]

Yes good write up indeed. However some pictures would help. Sorry I’m a visual learner. <br>So i spent at lease 10 hours on one window this weekend. And the reg was already removed. It was reinstallation of the reg and the window that kicks my a$$.<br>
Mother of GOD! It would seem when id install it correctly there’s was some kind of electrical failure. And when id install it incorrectly there was mech failure. i.e. arm popping off clip. Finally i get installed for the billionth time and now it only rolls up half way. This after going thru the instructions over and over and reinstalling the motor in various placements on the end and beginning of the motor cycle.<i> { I was lining the reg and the motor correctly as far as the teeth start and stop.}</i> <br> So after this un holy adventure and the final install attempted I went in the house, took a xanax, and had a glass of wine. This morning i get in my car and i go to roll up the passenger window and guess what? It only rolls up half way? WTF. I didn’t even touch that window! Is there some kind of memory reset for the motors? Could this be a comfort relay issue?<br> Please help.
<b> I'm about to go on a tri state killing spree.</b>

Unfortunately, this sounds like something that may be related to the comfort relay, which is often the cause of these sort of 'my car is possessed' type of behaviors.

Failing window motors/regulators are rarely so sporadic. Usually they die and that's that.

[martialartsblac]

Unfortunately, this sounds like something that may be related to the comfort relay, which is often the cause of these sort of 'my car is possessed' type of behaviors.

Failing window motors/regulators are rarely so sporadic. Usually they die and that's that.

Thanks, ill look in though that tonight, i love this forum. My girl friend thinks im some kinda bmw genius

[martialartsblac]

so now itve got it fixed and i had to go through and adjust the allen screw so tha it ligns up flush with the door rubber. NOW it rols up half way the n stops .like 4 times till its up all the way. anyideas?

[martialartsblac]

bumpage

[TKC]

Ok, I read this and began my attempt at the window fix. I've drilled out the 2 rivets no problem.
The first step in this write up is to put the window down until it's almost all the way down to undo a bolt. I can't do this since the window doesn't work, hence the project.
Anyways, I skipped that first step and drilled out the 2 rivets. I cant find what else is holding the regulator on? I looked all over for this "One of those is a 5 mm hex head bolt near the rear of the door. This is easily removed by reaching into the door with the 5 mm hex head socket on your ratchet handle."
I felt all around for a long time and found nothing. Any pictuyres? When you say Rear of the door, are you speaking of the side closest to the hinge?

[fun2drive]

I had to replace the driver's side regulator on a 92 318 which is a different regulator then the 93 newer ones. It has the motor and regulator as a single unit and is not repairable. Thus it cost about 300 from autohauz in Phoenix.
Since the window was moving down at an inch and up at an inch this indicated that the motor was ok but the regulator was toast.

I too had the pleasure of removing the regulator and motor but I did this. I used plastic clamps to hold the window in the up position and the sizzors with the window.
I do recall that there was something else that held the regulator in place after the rivets were removed but can't remember what it was. Anyway doing the replacement was pretty straight forward with no alignment issues since I kept the glass in place. I also lubed the plastic wheels and (very important) also lubed with silicon, the welting in the door channel. This will create a great deal of friction and wear things out if this is full of crude and have never been lubed with silicon.

I know I am not adding a great deal to helping do this repair but don't overlook the welting as I bet that is what caused my motor/regulator to act up...

[TKC]

Thanks for your reply. My regulator/motor is a single unit as well. I was planning on keeping the window held up with a clamp as well. I just need to figure out how to get that unit loose. Thanks!

[pmb212s]

I did this in my 318ti (which by the way is a pain because no manuals deal with the ti directly . . . Damn you crappy four banger) and did it appear obvious to anyone else that the problem can be prevented by replaceing the lubricant in the tracks, I did it on the passenger side and it works just as well as the drivers side which I replaced the regulator in.

[TKC]

^ That didn't help me. Anyone else?

[TKC]

Bump! How does the regulator/motor come out? Rivets have been drilled out. Thanks!

[tbreihan]

Ok, I read this and began my attempt at the window fix. I've drilled out the 2 rivets no problem.
The first step in this write up is to put the window down until it's almost all the way down to undo a bolt. I can't do this since the window doesn't work, hence the project.
Anyways, I skipped that first step and drilled out the 2 rivets. I cant find what else is holding the regulator on? I looked all over for this "One of those is a 5 mm hex head bolt near the rear of the door. This is easily removed by reaching into the door with the 5 mm hex head socket on your ratchet handle."
I felt all around for a long time and found nothing. Any pictuyres? When you say Rear of the door, are you speaking of the side closest to the hinge?

TCK:

My window regulators had either 3 or 4 rivets (I am pretty sure that it was 4), plus the 5mm hex-head bolt. The bolt is on the end of a long arm which extends from the main plate of the regulator toward the rear of the door. It is inserted through the arm from the backside (from the inside of the door) and screws into a large brass clip nut (like a threaded speed-nut) that is clipped on the inner door frame.

I am not sure what problem you are running into, but if you can, would you post a picture. I apologize for not having pictures, but I mainly interested in getting the job done when I was doing it, and I didn't have the time (or an extra set of hands) to snap photos of the process.

As far as lowering the window, it should be possible to push the window down even the non-functional motor. Of course, YMMV, but that was the scenario with my car.

Good luck, and send me some pics if you can.

Tim

[TKC]

Tim,

Thanks for the additional info, I will take some photos this evening when I get home from work. Thanks!
Toby

[tbreihan]

Tim,

Thanks for the additional info, I will take some photos this evening when I get home from work. Thanks!
Toby

No problem, and I am sorry that you are having so much trouble! Your car is a sedan correct? I have never seen the inside of a sedan's door, so I am not sure what the differences between your car and mine might be, but I imagine that there are some differences.

[TKC]

Tim,
Yea, it is a sedan and I am working on the rear passenger door. There were 2 rivets that, from the outside seemed adjacent to the regualtor. Upon drilling them out, they almost seemed to hold nothing??! So anyways, we'll have a better idea once I take photos tonight I guess. Thanks for the help and I'll put them up tonight.
Toby.

[Cochise]

i put a new fog light switch in recently & connected the ground to the positive and the accessory to the postive and the accessory to the power by accident so it blew some fuses, the interor light stopped working my passenegr headlight my passenger taillight electric mirrors and the drivers window. i replaced the fuses and everything is working except the mirrors and the drivers window HELP ME PLEASE

[forcefed]

Here's a late add to the thread but important and will relieve some stress. The initial writeup was excellent. i had to replace this system on my 95 M3 and didn't want to remove the window so i was relieved that someone found a way.

There are a few things that need to be added to make the story complete. first; I had the initial panic as some others did when my window only moved a few inches north after swapping the worn parts. so i resorted to the real manual and there is a section on reprogramming the motor/regulator after servicing. close your door, turn the key on, roll the window down, roll up, roll down, roll up, hold the up button for 5 seconds. this worked like a charm for me.

The second note is minor. The arm that swings aft from the heart of the regulator that has a 5mm screw holding it to the door panel is slotted. you can iterate a bit by moving the window up and checking that the back vertical edge is parallel with the trim on the car. adjust as necessary before buttoning up the panel.

Last, use the dremmel!!

thanks for the post.

[christran12]

After reading and then re-reading and then re-reading again all the posts here, I finally made the jump at replacing my Electric Window Motor. With all of your tips, it made it a 1hr and 20min job. No joke. And Yes, the Dremel is what made it a snap! Probably had something to do with the fact I set the damned thing at the highest speed possible. With sparks flying, its probably good to put on a pair of safety glasses which I did as soon as the first spark flew. I expected quite a few disc to break and fly apart. But only one did. The others were simply worn down, went through three of them, much less than expected. Just cut a tic-tac-toe pattern into the screwhead. Then using a heavy and broad pair of pliers, you just squeez and swist until they're gone for the most part. Now just use some moderate blows from a hammer to phillips screwdriver right to th middle of the rivet and it easily falls out the otherside. In my case, I just replaced the motor. The regular works fine. Just need to some re-greasing. Even with the added R&R of the motor on to the regulator, it still took less time than I ever imagined. For ease, I replace the rivets with 6mm slotted screws so that it would be easier to keep the new screws from turn while I'm tightning the locknuts. The window now works better than the passenger side. Gonna open that baby up and pile on that lithium grease and hope to breath some life into it before the motor gives!

One little note. Lifting and lowering the window while the motor wasn't working wasn't as easy as you guys describe (just pushing and pulling on it). I actually had to remove the metal housing for the Magnet coils on the motor and twist it to lower or raise the window. The good thing was I had already romoved it previously since my window was stuck half open two weeks ago, this was the only way I found to raise it. So I left motor partially disassembled. But from there on, it was a sinch.

BMW's TIS service manual doesn't even come close to the posts you guys left. You guys rock! Cheers!

[baigeman]

How many magnets (1 or 2) did you have in the white plastic housing that goes around the shaft on the window motor that goes into the regulator?

I have a lot of metal dust in there an am wondering if a whole entire magnet broke off and ground away!

[baigeman]

It is a pain but possible to remove the window motor without removing the regulator or the window or any of these other components.


I did this to check and see if my problem (window stuck 4 inches open) was the motor or the regulator or seomthing else.

The first thing I saw was very nasty and do not have a picture of. MY VAPOR BARRIER FELL DOWN AND GOT STUCK IN THE REGULATOR GEAR! And this got a lot of that thick black vapor barrier adhesive all over the gear and most likely inside the regular. This probably explains why it is very hard to move the window up and down even with the motor removed.

Here are a few picutures of the different pieces of the window motor and some other pictures for reference to help anyone looking inside their door.

[bmtroubleu98]

Best way to remove rivets is with a cold chisel...chisel head off rivet then use a pin punch to knock it out...takes literally 5 mins to do.

[baigeman]

Not that I have everything all lubed up and running smoothly I need to try and put my motor back on the regulator. This seems to be very diffivult, i am guessing since the regulator is still attached to the window and eveything else so there is pressure on teh gear inside it.

Any thoughts on getting the motor to fit back into the regulator gear? I have tried forcing it in while turning it as well as moving the window up and down very slightly to get it to slide in. I even plugged the moto back in and tried pushing it in while tapping the button a little to see if it owuld grab.

[christran12]

You've disassembled just the lower drive coil section of the Motor assembly. I had already done this to be able to turn the window up and down manually. But this doesn't fix the problem. Chances are, the upper assembly (electronics, shaft groove and drive gears) above is probably messed up as well and should be replaced as a whole. Thats where you'd have to remove the regulator since the motor assembly is screwed in from the inside of the regulator. I think it would be worth your while to remove the regulator and replace the rivets. It makes any future work much much easier. My passenger window works (although its a bit sticky and slow), but I'm thinking of removing the regulator,cleaning all the guides and piling on the lithium grease. For the joy of it, I'll be replacing the rivets here too. Better get out the safety glasses.

As for using a chisel. I thought about this, but, fact is, the metal frame that the regulator is attached to is pretty thin. The rivet's head is pretty think and rebust and I would guess it would take quite a bit of force to do the job. I'd be wary of damaging or warping the frame pounding on it.