74 Window Mechanics

JayWltrs

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Front and rear passenger windows finally gave up the ghost. As noted in the primary window write-ups by others, the procedure for swapping to E28 motors isn't as complicated in the 74. But the regulator is very different. A couple of questions/observations:

1. I don't see bump-stop screws or their mounting tabs on the regulator like on the early E9 or E28 regulators. There is a white plastic disc that looks like it might serve a similar function. Is this correct or have they just disappeared and I need to find a place for them (found nuts, washers & horsehair in the door, but no stops)? Some pics (will add backside pic later):

Window Gear 1.jpg

Window Gear 2.jpg


2. The tracks/guides have the hardened molasses, which was pretty easy to clean on the regulator once removed. But I'm hesitant to remove the tacks because I'm not sure I'll ever get them back in correctly, and I'm worried about destroying the already damaged flat-head screw/bolt. Not to mention that it will significantly expand the scope of work for 4 windows if I have to remove the upper trim to get them out. Buck up or clean them in place?

Window 4.jpg

Windows 3.jpg
 

Gary Knox

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Jay,

Those rubber bump stops should be there. Time to install new ones! I was able to clean my door mechanism and tracks fairly well 'in situ' by using quite a bit of Brake Cleaner spray (lots of paper towels in the bottom of the door to absorb the gunk and cleaner), then applying some SuperLube in the appropriate places. I removed the rear window mechanism to clean it. The cleaning and the e28 motors took the time for either up or down from about 20 seconds to 6 seconds for either F or R windows.

Gary-
 

JayWltrs

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Jay,

Those rubber bump stops should be there. Time to install new ones! I was able to clean my door mechanism and tracks fairly well 'in situ' by using quite a bit of Brake Cleaner spray (lots of paper towels in the bottom of the door to absorb the gunk and cleaner), then applying some SuperLube in the appropriate places. I removed the rear window mechanism to clean it. The cleaning and the e28 motors took the time for either up or down from about 20 seconds to 6 seconds for either F or R windows.

Gary-

Thanks, Gary. I'm going to take the cover over off the driver's side and compare to make sure I'm not crazy or missing something obvious. I have the SuprerLube ready to go! I dont't use brake cleaner as much anymore. It took barely 10 mins to clean the gears and regulator with careful use of PSC 1000 in the parts washer and a nylon brush. It's my new favorite stuff at $50 for 5 gals at Tractor Supply--not as toxic, noxious smelling, or expensive as the hard core stuff, but it works amazingly. That's one reason I would like to remove the tracks. I can clean them 10x faster and better if I can remove them--just doubting myself as to whether I can get them back in correctly.
 

JayWltrs

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Front windows don’t have the same stops:

427EB24A-F5DB-405B-ACF4-D8BE3C60FA78.jpeg


The flat plate was covered with a foam pad that holds moisture and was the only part with rust. Not sure what type of pad I’ll replace it with after paint, but it won’t be a sponge.
 

JayWltrs

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The baked molasses gummed up and froze the track wheels—I was afraid they weren’t salvageable. Required lots of patience, fluid, soaking, brushing, dental floss, multiple passes, etc.


E31DDD1A-A2C4-4783-9911-F5AA150CD95C.jpeg
 

bavbob

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This raises the question I have concerning lube on the front (manual) windows. The bearing unit needs to be greased but why the track? Seems to create a lot of problems later. My slide so nicely after cleaning all that molasses off and just lubing the bearings.

BTW there was a post a while back with an image of a spring and asking what the spring went to . Those two cups on that unit are supposed to be flipped to face each other and have the spring in between them.
 

JayWltrs

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This raises the question I have concerning lube on the front (manual) windows. The bearing unit needs to be greased but why the track? Seems to create a lot of problems later. My slide so nicely after cleaning all that molasses off and just lubing the bearings.

BTW there was a post a while back with an image of a spring and asking what the spring went to . Those two cups on that unit are supposed to be flipped to face each other and have the spring in between them.

I think this is an excellent idea and will try before closing. Might at least need some dry teflon spray on the tracks to protect the bearing surface. Cleaning the hardened stuff is bad, but probably easier than finding replacement bearings.

Missed the spring post. I'd have never figured it out had it not been there. I couldn't really see the plastic cups until I'd removed the 2nd or 3rd layer of goop. Then I thought the cups were a single broken part, until I freed it up some more and the lights came on as the spring popped out.

The 74 motor deserves some torque respect for raising and lowering the windows at all this last year through what's essentially glue.
 

JayWltrs

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I never got back to this, but I'm about to embark on another window, so I thought I'd follow-up. The 1974 regulators (which I believe @HB Chris said changed in mid-73) do not have the rubber- or spring-headed bumpstops. If you have a later coupe and this regulator, ignore all the bumpstop advice for the front windows. Honestly, most of the discussion of the earlier regulators will just confuse. I'm guessing this might be what happened to Bill Arnold with @scottevest

Instead, they have two metal tabs that stop a nylon disc that rotates around the gear. Here's how it looks and where you can adjust from outside (You can see the disc resting on the stop on the right of the top hole):

1569527844670.png


I'm not alone, there is a thread I missed that goes through the same process of realization I did. https://e9coupe.com/forum/threads/drivers-window-has-stopped-working-suggestions-sought.9572/page-2

1569526327293.png
1569527071648.png


The door on the that thread was cut, and removing the regulator might be possible with the motor attached, but I couldn't do it. Because, I think, it sits at a 90 to the regulator and generally makes the assembly wider than the earlier models, esp. with the 74 motor (E28 motor shown above). Chris or someone mentioned this somewhere, but the light didn't go on for me until blood, cursing, and bourbon flipped the switch. Definitely have to get the window up and out of the way. I ultimately had so much gunk everywhere, I just removed the entire window and back rail.

The motor and regulator sit forward of the front rail, and there's just not much room to get it all past there. The bump behind the door brake also makes it tight & prevents rotating it downward. (I had to cut/grind off the back tab of the brake to fit it.). I also don't know if it was just me, or if any extra support in the 74 door makes it narrower.

1569528264213.png



And here's how the spring sits in the rail bearings mentioned earlier. Don't know if this roller mechanism is the same in earlier cars, but I couldn't find a hint of new or used ones online, so I treated it with extra kindness and soft words. The spring isn't held in place until you get it into the rail, making for a two-hands-with-a-thumb-holding-it-together process to thread it back into the rail.

1569529035779.png
 

aearch

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YEP YOU HAVE IT
I GREASED EVERYTHING
ESP THE TRACKS -THAT WHERE ALL THE GRIME GETS STUCK IN
I USED HEAVY GREASE ON THE MECHANISM AND LIGHT WHITE GREASE ON THE TRACKS
SO IT DOESNT HARDEN OVER TIME
GOOD JOB
 
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