Replacing rear window motors ? how to

damienh

damienh

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I guess a few people have done this, not sure how to do it.

Any help appreciated.

Damien
 
Do you want to just replace them, or do you want to upgrade them with the E28 ones?

Also, have you tried just cleaning out the old ones? They are much faster when the track is cleaned off and the grease repacked.
 
I'd love to replace them with e28 ones but I have none !

For now I'm swapping with the motor from my donor car which at least work, I did the driver's front a few weeks ago and it works fine, although very slow.

I'm pretty sure the rear motor is also the problem, but I can't see how to get it out. I'm told the window needs to be lowered, but I can't lower it, as it doesn't have that little plastic spindle I've read about to turn.
 
Ah, so you are in the same situation I was in. In order to remove the window motors, the window does need to be down. The window transmission is probably stuck. The transmission is a worm gear coupled to a plastic spur gear. The plastic spur gear gets deformed if the window is left up too long. You can try and lower the window by directly turning the worm gear. It will be slow, and it will be difficult.
 
Yes I've seen exactly that mechanism, it has a covering plate, I guess I could find something to turn it. It doesn't make any noise though, I'd expect to at least hear something trying to move the transmission ?

My front was the same, nothing at all when I pushed the button, I just swapped the motor over and it worked.

I guess I can look for deformation in the plastic.

Do you know the process for removing it if I do manage to get the window down ?
 
The German engineers, in their brilliance, put all the bolts to secure both the motor and the transmission on the other side of the regulator, meaning you have to snake your hand between the regulator and the window when the window is down and the regulator is out of the car.

Mine barely made any noise, either. If you have another one, perhaps the fastest way to do it is to take a drill or a dremel and just de-tooth the plastic gear. Then you can just push the window down, unless the regulator itself is jammed. Most of the other guys really don't like that approach, I don't like it either, but I couldn't get the thing down any other way.
 
Ah ok, I see now. Yes I also don't like the sound of that approach ! it will be a last resort.

So the window doesn't need to be removed, but the regulator does is that right ?
 
almost forgot - the chrome trim, does that need to come away so you can get your hand down the outside of the glass ? I can't see how it's attached
 
Ok, hang on a sec, I just looked at a picture of my rear regulator, when I was upgrading/fixing them.

[Broken External Image]:http://www.prism.gatech.edu/~gtg982h/pics/regfront.JPG

As you can see, the motor tabs stick towards the inside of the car, meaning you can unbolt the motor from inside the car, not requiring you to remove the complete regulator setup. To change the transmission,m though, it looks like you have to. Once the motor is unbolted, you just have to pull down on it to remove it from the rubber coupling which connects it to the transmission.
 
Atlas
If I remember correctly, your window got broken during this project.
Good tech info article!
I always come to the group when a problem arises. A great amont of knowledge to share.
steve in reno
 
Window upgrade

I understand that the upgrade for the front and rear window motors is to use an E28 rear motor. The question I have is what year e28 or does anyone have a part number for the motors? Also, I have seen a write up on how to wire them up, does anyone know where this can be found?
 
Atlas
If I remember correctly, your window got broken during this project.
Good tech info article!
I always come to the group when a problem arises. A great amont of knowledge to share.
steve in reno
Click to expand...

Yep, and it was thanks to Dave in NC's kindness that I have one now. Thanks again Dave, although I haven't seen him on the board in a while.

As for the E28 motor, any year will do, but only the rear window motors.

I swear, if my dad ever says "We'll just knock it loose with a hammer" again, I'll take the hammer to him! :D

Part number is here:
http://www.realoem.com/bmw/showparts.do?model=DC74&mospid=47231&btnr=51_0372&hg=51&fg=10

Main window thread:
http://e9coupe.com/forum/viewtopic.php?t=458&highlight=window+upgrade

Search is a valuable tool, there's a ton of info on this board, if you poke around for it.
 
Thanks Xatlas. Managed to separate the motor from the transmission and get it out, by pulling down the black plastic cover and accessing the two screws holding it in place. After loosening it, it was possible to slide it out without destroying teeth.

I was pretty pleased with myself until I pressed the switch to hear a single click sound, and nothing happening.

I'm sure I tested it a few months back.
 
"I understand that the upgrade for the front and rear window motors is to use an E28 rear motor. The question I have is what year e28 or does anyone have a part number for the motors? "
Click to expand...

Steve I don't have the part number but have pulled a lot of rear window motors from E-12 and E28 models at the local pick and pull and they are very similar. I think any year E-28 ( 533i, 528i, 535i 83-88 ) will work fine.

"Also, I have seen a write up on how to wire them up, does anyone know where this can be found?"
Click to expand...

I did the front window conversion on the drivers door in my 72 CS this spring and just did the same on both front front windows on Shawn's car a few weeks ago. I wrote up the procedure here: http://kdelimon.googlepages.com/windowmotorconversion2

There are a few minor differences on the cutout for the passenger side but
you'll figure out out when you get there.

Some other write ups that might be of interest

Front Door panel removal:
http://kdelimon.googlepages.com/doorpanelremoval

Front regulator disassembly:
http://kdelimon.googlepages.com/frontregulatordisassembly


-Kurt
 
Wow, these instructions were very well documented! I hope we can store this away somewhere so we don't loose it.

Nice job kurtd.
 
Truely a great write up on windows.

As far as the part numbers of the E28 rear motors
I found that the part numbers 51 35 1 375 397 and
51 35 1 375 398 were on the following models. They are
still available new.
535i from 1984 to 1987, 533 1984 only, 528e 1984
to 1987 and the M5 1986 and 87. I did not look for the E12
based motors. I did see one that was NLA.

Like it was mentioned, is there a folder/file that this type
of info can be stored for the 3.0 group reference? Something
like the Norn Grills Big Coupe Group repair site??
 
Great instructions

Thanks Kurt for such a well written piece. Easy to follow and my swap is now done.

How about for the rear windows, similar process using same replacement motors? If so, I'm back to the pick and pull for 2 more!

Thanks again,
Tom P
 
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