New Member/ Drivers Window

174kup

174kup

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Hello to all. My name is John and I'm new here on e9coupe.com I'm the proud owner of a beautiful '74 CSi Granatrot Metallic example previously owned by Peder Mansson (Sweden & Switzerland) and before Peder, Mr & Mrs Arthur Wegweiser (Pennsylvania). My compliments to Peder, (an active member here on e9coupe.com) for taking such great care of the car!

DRIVER SIDE WINDOW FREEZE-UP
The driver side front window of my would not go down. But when activating the switch up or down a slight click could be heard coming from inside the door. After consulting with HBChris, I removed the door card to investigate. With the door plastic peeled upward, I could see the "sardine" style motor and observed a rubber "bushing" (about 1.25" long. See Photo) connecting the motor drive shaft to the regulator drive shaft. When activating the window switch, I could see the motor "trying" to turn the rubber bushing (the motor driveshaft would turn just slightly but the top of the bushing remained motionless) but unable to start spinning. I then manually turned the rubber bushing while activating the window switch, and the motor started spinning, and window retracted! Original problem solved, for today....

Now for some questions:
Why might the regulator shaft have resisted turning initially?
What might prevent the regulator drive shaft from "freeze-up"? (if that was the culprit). Is it possible the regulator worm gear is wearing out?
Does the window "upper limit" rubber stop need to be adjusted slightly to prevent window from going so high?

By the way, everything looks well-lubricated with fresh grease.
 

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That's one of the more common issues with these cars. The "sardine can" motor-gearboxes are just marginally powerful enough to raise the windows, so if the windows aren't used regularly, the temperature changes, or the car just wants some attention, they get stuck. My '70 has a hole in the door card, covered with a plug, that allows access to that rubber coupler so that you can start it turning without having to disassemble the door. Did these access holes go away in '74?

One solution is to improve the lubrication and re-align everything to reduce friction in the system. Another is to swap in e28 rear motor-gearboxes which are more powerful. Lots written on these topics here on the e9 board.
 
My guess is the window is jamming up against or overloading the crusty rubber bumper stop. Can you get the motor free by spinning by hand to lower the window a little and get things moving? Then loosen the bump stop and extend it a little so the window doesn't leverage down on it so much and jam.
 
His rubber stop looks new and adjusted properly. His CSi is a 74 so someone installed those sardine can motors, not BMW, it was originally a manual.
 
HB Chris said:
His CSi is a 74 so someone installed those sardine can motors, not BMW, it was originally a manual.
Click to expand...

Ah, now I get it. Yea, I had thought that '74's had the later/better motors, but figured maybe there were early '74's and late 74's or some such thing. So whoever did that conversion had to add all the wiring, as well as the motors and regulators. Seems like a lot of effort to convert simple, reliable manual windows to marginal electric ones!
 
Thanks Steve, it is not needed I assume as the hole in his door card is up higher where the crank would have been. If it sticks, can it be the gear box itself? Before removing the entire regulator John is trying to sort out whatever he can.
 
in my experience with my finicky windows, one turn can make the difference between jamming and releasing properly. His looks all the way flush with lots of exposed threads which suggests too much travel for the mechanism and thus possibly stuck over center

HB Chris said:
His rubber stop looks new and adjusted properly. His CSi is a 74 so someone installed those sardine can motors, not BMW, it was originally a manual.
Click to expand...
 
Typically gear failure is it spins in place where the plastic gets destroyed by a stuck mechanism and working motor
 
Nice to meet you, John. I love that color!

I just reworked my driver’s window again. Its problem mainly was that it really struggled to lurch out of its initial, fully-up position. It would otherwise move up and down as commanded, though slowly. Is this what you’re describing? What fixed it was replacing the rubber u-channel guide on the front edge of the window, in the vent window assembly. The glass had worn in a divot down inside the door. The lower front corner of the glass was digging in instead of sliding downward. If you shake the glass with your hand while operating the switch does that get it moving?
 
A long time ago Art Wegweiser told me that when putting the coupe away for the winter, do not put the windows up all the way. Leave about 1/4" open. Sometimes when up all the way the force (like Star Wars?) make the window not want to open.
 
Stan said:
A long time ago Art Wegweiser told me that when putting the coupe away for the winter, do not put the windows up all the way. Leave about 1/4" open. Sometimes when up all the way the force (like Star Wars?) make the window not want to open.
Click to expand...
Putting the windows up all the way would squeeze the rubber on the stopper end making its swell up to the sides . If left for a long time closed it makes the rubber hold its squeezed shapes which swell up to the side and rubs against the frame of the regulator slowing it down acting like a rubber brake!
While back I tore open the mechanism completely, every piece was out , cleaned throughly and Lubricated well. Then I open the sardine motor to pieces and had all its guts out and concluded these motors are built like a tank! They are very durable old school motors made to last for the life of the car! However after installing it on another E9 using it for while and then swapping it with E28 ear motor I timed both motor types and concluded the E28 is faster! Furthermore the sardine motors are more sensitive to current going through the switches .
 
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