Rear window motors

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x_atlas0

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Hello everyone, and happy 4th of July!

I am in the middle of a semi-complete interior tear-down so I can figure out what a moronic audio installer did in the 80s. I am having trouble getting the rear window regulators out, as they are both stuck up. If someone could mark where to try to manual crank the rears, I would much appreciate it. I am at the point where you have to remove the top trim section by undoing the screw that is behind the rear window, in its channel, so the only way to remove this screw, and therefore the trim section, is to lower the window.
[Broken External Image]:http://www.prism.gatech.edu/~gtg982h/regulator.JPG

Any other suggestions on where to go from here would also be appreciated. The motors seem to be on their way out, so if someone could also post a picture of the e28 motor retrofit, it would be excellent. Have a happy 4th, everyone, although I imagine to our international members, it is simply another day.
 
Between the motor and the gearbox, there is a ribbed whitish plastic part with a rubber part just above that. You turn one or the other of those, whichever is easier, many turns to lower the motor. And yes, you have to do this to get the whole regulator assembly out. Sometimes, you can feel a little movement at the white ribbed part if you push the window switch, just don't get your finger caught if it suddenly frees.

I've done this several times and usually find that something in the whole regulator assembly is locked, but once freed, the motor-gearbox assembly will turn. It may help to spray some good penetrating oil on the motor bushings at either end.

Once you have the whole assembly out of the car, remove the motor and gearbox. Clean the old grease out of the gearbox and put in something like wheelbearing grease. Work some oil into the motor bushings and I am pretty confident you will be able to make these motors usable. I don't remember ever finding one that I couldn't make work. Of course they are still slow compared to modern cars, but if you clean and lube all the regulator parts as well, can be made to work acceptably.
 
From my limited experience the gearbox is the weak link. Last time I got one from Mike Pelly and worked great. Cleaning up the rails, the motors, and the switches gets everything working again. If you are convinced the motor is tired, Mike had at least one available as well.

The white plastic can be rotated with your thumb until the window is down.
Disconnect the window from the regulator arm and remove the regulator.
Be careful when you separate the gearbox from the regulator, as the regulator is wound and will unwind fast and push the arm hard.
 
Well, after many hours of turning, pushing, pulling, and swearing, I decided to ask my pops for some help, since he has been doing this sort of thing for far longer than I. This is what I ended up with:
[Broken External Image]:http://www.prism.gatech.edu/~gtg982h/busted.JPG
So if anyone has some rear glass, shoot me an email or PM, and we will do business.
 
window motors

Unfortunately for you the E28 rear window motors will not fit your early coupe. The E28's have a gearbox integral with the motor, and an 8 tooth gear which engages directly with the big regulator gear. This is the kind of mechanism in the post 74 coupes...
BTW, are you still speaking to your pop ???
 
Re: window motors

Unfortunately for you the E28 rear window motors will not fit your early coupe. The E28's have a gearbox integral with the motor, and an 8 tooth gear which engages directly with the big regulator gear. This is the kind of mechanism in the post 74 coupes...
BTW, are you still speaking to your pop ???
Click to expand...

Yeah, we are still ok, since he is buying said window...

The PO put the e28 motors up front, so I know what you are talking about. However, to put them in back, why not simply remove the worm gear set, as that attaches to a small 8-tooth gear which turns the regulator gear, and replace it with the 8-tooth gear from the e28 motor directly? This was why my motors have only two poles going to them, causing lots of confusion when I was trying to get the fronts to work.

Right now, the fronts do work when direct power is applied, and worked using the original (black with chrome surround) switches, but I can't for the life of me figure out how they (the audio installer) made it work. The original switches worked by placing the same voltage over both terminals until it hit a block closer to the motor, which somehow put one of them to ground, causing a voltage difference to drive the motor. I have been going off a 733i diagram on how they wired up the power windows, and it looks like there is a relay for this purpose, although I can't seem to find it.

As for the rear system, after getting it off and loking over it, the main regulator gear seems to be frozen, as I can't move anything, even with the motor removed. Any hints on where to start?
 
Re: window motors

Right now, the fronts do work when direct power is applied, and worked using the original (black with chrome surround) switches, but I can't for the life of me figure out how they (the audio installer) made it work. The original switches worked by placing the same voltage over both terminals until it hit a block closer to the motor, which somehow put one of them to ground, causing a voltage difference to drive the motor. I have been going off a 733i diagram on how they wired up the power windows, and it looks like there is a relay for this purpose, although I can't seem to find it.

As for the rear system, after getting it off and loking over it, the main regulator gear seems to be frozen, as I can't move anything, even with the motor removed. Any hints on where to start?
Click to expand...

Oh boy your having fun!
but glad you and your dad are still on speaking terms....

The E9 window circuits do not have relays, but were fitted with circuit breakers, usually push button type trip swtiches located on the panel under the streering wheel, same panel with heated rear window/hazard and fog light switches.
Be warned some early cars did not have these circuit breakers! They were fitted after complaints of window motors burning out, trapped hands etc etc. They are supposed to "trip" when the load gets too high.
If present make sure they are working.

In regard to the rear ones first make sure that the switches in the rear arm rests are ok and or working, before pulling the window.

The mechanism is somewhat complicated because the window tilts as well as going up and down and usually seizes due to lack of use. Taking it out is relatively straight forward, but the glass has to be dropped down or removed before taking the assembly out.

If required I can let you have the "official" wiring diagram for the front and rear windows - let me know

Good luck
Malc
 
Re: window motors

Oh boy your having fun!
but glad you and your dad are still on speaking terms....

The E9 window circuits do not have relays, but were fitted with circuit breakers, usually push button type trip swtiches located on the panel under the streering wheel, same panel with heated rear window/hazard and fog light switches.
Be warned some early cars did not have these circuit breakers! They were fitted after complaints of window motors burning out, trapped hands etc etc. They are supposed to "trip" when the load gets too high.
If present make sure they are working.

In regard to the rear ones first make sure that the switches in the rear arm rests are ok and or working, before pulling the window.

The mechanism is somewhat complicated because the window tilts as well as going up and down and usually seizes due to lack of use. Taking it out is relatively straight forward, but the glass has to be dropped down or removed before taking the assembly out.

If required I can let you have the "official" wiring diagram for the front and rear windows - let me know

Good luck
Malc
Click to expand...

Dropping the glass was the main problem, we could not get the thing to go down. The plastic gear connected to the motor could turn just fine, but the gear was not turning the worm gear any more, making it pointless. Even with the regulator out and no glass in the thing, I cannot seem to get the system to go down at all. I am not sure how to make it go down, either, as I have never actually seen the rear window movement.

My coupe does not have this breaker system you are talking about. I have the Blue Books, so I am not in dire straights for a circuit diagram. Thanks for the offer, though. The rear window motors, when the rear switches are activated, make the click noise to show they work, but are stuck.

Hopefully the other side will be less of a hassle, but at this point, I am preparing for the worst.
 
rear window logjam

Hey Matthew, will try to talk to Ray tomorrow.(thur). If that window is out you are welcome to it. We'll trade blue-book shipping or something. Check out the beautiful CSL pictures next to this post. I think that your dad can fix that rear window...(being RHD, it's his pass side rear) Dave
 
O great coupe gods of yore, I beseech thee for aid...

Here is the regulator, out of the door:
[Broken External Image]:http://www.prism.gatech.edu/~gtg982h/regback.JPG
[Broken External Image]:http://www.prism.gatech.edu/~gtg982h/regfront.JPG

Even with the motor removed, I cannot get the main regulator gear to budge, at all. I have tried turning the worm gear to no avail. I also don't see any bolts/nuts, so I can't take the bloody thing any more apart than it already is. Help would be much appreciated.
 
If soaking all joints, post connections etc with WD40 or similar for 24 hours doesn't work then....


Time for drastic action :shock:

1].....Remove all the plastic parts
2].....Apply heat to joints to offending parts, do not overheat! No Cheery red!
3].....Apply light oil to offending joints, posts etc while hot.
4].....Try to move offending parts.

Repeat 2 though 4 until free

BE CAREFUL!
Wear appropriate gear, especially safety glasses
Don't set the garage on fire.
Don't use too light an oil, it will bust into flames!
Have a fire extinguisher handy!
Don't burn yourself!
Don't heat any springs or wound coils they will loose their temper

Use a "fine" flame, from an Oxy-acetelene set if possible, propane will work but most systems have large flames

This apparently brutal method will work, having freed off many "siezed" parts using this method.

Malc

PS Added: You may have to prise out some parts, such as the plastic gears etc, they were often push fits, becareful as they get brittle with age.
 
If soaking all joints, post connections etc with WD40 or similar for 24 hours doesn't work then....


Time for drastic action :shock:

1].....Remove all the plastic parts
2].....Apply heat to joints to offending parts, do not overheat! No Cheery red!
3].....Apply light oil to offending joints, posts etc while hot.
4].....Try to move offending parts.

Repeat 2 though 4 until free

BE CAREFUL!
Wear appropriate gear, especially safety glasses
Don't set the garage on fire.
Don't use too light an oil, it will bust into flames!
Have a fire extinguisher handy!
Don't burn yourself!
Don't heat any springs or wound coils they will loose their temper

Use a "fine" flame, from an Oxy-acetelene set if possible, propane will work but most systems have large flames

This apparently brutal method will work, having freed off many "siezed" parts using this method.

Malc

PS Added: You may have to prise out some parts, such as the plastic gears etc, they were often push fits, becareful as they get brittle with age.
Click to expand...

Why o why can it never be something simple with this car, ever?

So you want me to use thermal expansion to free up the joints without setting the whole thing on fire. Oook... I think I can try that, although my next update may be from the burn ward.

Although... won't quenching it with the oil cause the metal to thermally fatigue, causing crack failue?
 
Remove the little gearbox first

Before you do anything else, remove the little gearbox that the motor drives. It is held to the regulator by 2 bo.ts. It may be what is binding. With it out, you should be able to more readily move the regulator parts.
 
Bill is right, the gearbox may be what is binding.
It may have all three bolts, two are easily removed, the third is
a Phillips only accessible through a hole in the regulator gear wheel. If it is not moving you may not be able to line the hole up. Maybe force the gearbox plastic gear out even if you break it. Keep the pictures coming, we landed
on the moon and will get a window to work...
 
Don't worry, Be happy! :p
This all adds to the fun of owning a classic car and remember we are here to help and bring you flowers in the burns ward :wink:

Seriously just take your time, If required walk away for a few days and forget about it
Anyway you might find by taking the remaining bits off you can get it to move and if worst comes to the worst we can russle up some working window frames for you

Hang in there
Malc
 
I finally got the damn thing down! I managed to remove the worm gear transmission with the bar in the way by very carefully pulling the regulator bar back a ways using a hammer's pullers coupled with a very tiny 8mm open-ended wrench. As soon as I removed it, I was able to move the window with a minimum of force. Now, I am going to attempt to figure out why the worm gear set is frozen. Pics later.
 
Why it is frozen? Metal on nylon gearing? Poor planarity of axis of rotation?
Why ask why? Get a fresh one and you are done.
 
Just post brought to mind something I encountered in 2 different coupes - stuck rear windows. I found the white plastic gears unmovable or I ended stripping one with a wrnech out of frustration (had an extra motor and gear). ON the first window I too removed the motor and regulator and found everything worked fine (when not installed). Once reinstalled the window again froze.

It turned out that the old/gooey rubber bumper or stopper that limits the sweep of the window had become welded to its opposing part. For obvious reasons this prevents window movement. The quick fix was to slide a razor blade between the two sufaces. I literally had to do this for all windows. First applied white grease to the rubber but ultimately replaced the rubber with new from marine hardware supply.
 
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