WTB: front driver side window motor for late 73 or 74 model
- Thread starter Bmachine
- Start date
Bo, I’m sure I have a motor, probably e9 not e28.
wow I've never seen one of those break
Yes It REALLY caught me off guard. It looks like that housing was just pot metal or something...
But it also made me wonder, if there is any safety trigger inside the motor that stops it when the "stopper" hits the top or the bottom of its travel. That's a lot of torque that is still energized.
Thanks a lot Chris!
Now I thought the e28 motors only worked on the rear. I have a spare e28 and although it does appear to fit, the cogged wheel coming out of the motor sits lower relative to the housing. This means that the wheel only engages in about half of the thickness of the teeth on the regulator. See photos. Late style e9 on the left, e28 on the right.
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Rear e28 motors work on all coupe windows. I think you don’t have them lined up parallel they will work fine.
I actually installed that e28 one on the regulator. Everything seemed to fit fine but then I noticed that the cogged wheel sat lower than I remembered. I then compared it with the one from the passenger side (which still has the e9 motor) and that one definitely sits higher and engages the full width of the regulator wheel teeth. I can see how this could "appear" to work ok at first, but, over time, since only the bottom half of the regulator teeth are in contact with the motor cogs, they would start to rip.
But I will go and re-do the test in case I missed something just to be sure.
But I will go and re-do the test in case I missed something just to be sure.
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I reinstalled the e28 motor with same results. Here are some photo comparisons with my passenger side which still has the original setup. The e9 motor cogs protrude past the teeth of the regulator while the e28 one only “covers” about 2/3 of their width.
E9 on left, e28 on right.
E9 on left, e28 on right.
Do you have washers on the e28 mount points but not the E9?
Check the post that the gears sit on, one is too low. They need to mesh 100%.
Sorry I should have addressed that. I also noticed what looked like a washer. So I went to double check. It is not. It is actually part of the casting. The angle does make it look like a washer.
jmackro
Well-Known Member
Bo: The distance between the gear and motor housing isn't what's important; it's the distance between the gear and the faces of the three mounting bosses on the housing. Looking at your photos, that dimension doesn't look that different between the e9 and e28 motors. Yes, the e28 gear is closer to the housing, but the bosses are lower as well.
I'm looking at the boss on the e28 housing visible on the far right side of the photo below. Notice that it's diameter at the top is stepped down a bit. What if you filed off that stepped-down length? Would that allow the gear to mesh fully?
Better to listen to that Jay. I’m not sure what’s going on. I have 3 e28 motors that all line up correctly—I’m not a hoarder, only 1 works well.
Hi Bo,
I've got a couple e23/e28 window motors on the bench now. Mine look a bit different than yours - 1) mine having the gear drive standing out a little taller and then also 2) the back-side cover plate on mine has an access hole. If you search out on ebay for e28 window motors you will see the same - perhaps you have a close version but not best? I have not yet fit these into my e9 but with the taller drive gear i expect it will be as the guys say it should fit.
I've got a couple e23/e28 window motors on the bench now. Mine look a bit different than yours - 1) mine having the gear drive standing out a little taller and then also 2) the back-side cover plate on mine has an access hole. If you search out on ebay for e28 window motors you will see the same - perhaps you have a close version but not best? I have not yet fit these into my e9 but with the taller drive gear i expect it will be as the guys say it should fit.
Very good suggestion as usual, Jay. I will try that.I'm looking at the boss on the e28 housing visible on the far right side of the photo below. Notice that it's diameter at the top is stepped down a bit. What if you filed off that stepped-down length? Would that allow the gear to mesh fully?
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Really interesting observation, coupesport. I did not know there were two versions of the e28 motor. Could you please list the part number that is printed on it? Mine ends with 821 027.
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jmackro
Well-Known Member
Well, the front and rear e28 motors are different. Is it possible that Bmachine has a front? I've got e28 rears in my e9 and they work great; however, I've never seen what an e28 front looks like. Maybe the protrusion of the gear is part of the difference.
Front E28 has 10 teeth—I pulled a set when I pulled a pair of rears. It also has the hole on the back of the motor body. I thought the rear E23s also had 10 teeth, but it looks like coupesport has some w 8.
Bo,
Jay Mackro's fact disqualifies my motors as they are not e28 rear. Mine are for my e23 maintenance project and I can say the e23 front and rear and the e28 FRONT are all the same. However Jay knows the e28 rears are different and this current ebay offering for rear e28 motor shows similarities to yours (https://www.ebay.com/itm/BMW-1975-1...4:g:AEkAAOSwKmVei5Tc:sc:UPSGround!60137!US!-1).
The hi-def pic shows the same part number as yours (680-23693-4). So that may be your solution.
Jay Mackro's fact disqualifies my motors as they are not e28 rear. Mine are for my e23 maintenance project and I can say the e23 front and rear and the e28 FRONT are all the same. However Jay knows the e28 rears are different and this current ebay offering for rear e28 motor shows similarities to yours (https://www.ebay.com/itm/BMW-1975-1...4:g:AEkAAOSwKmVei5Tc:sc:UPSGround!60137!US!-1).
The hi-def pic shows the same part number as yours (680-23693-4). So that may be your solution.
Bo- I have boxes of e28 window motors at the shop, do you want to try another motor? I can mail one out tomorrow.