Creating a standalone thread after discussing the subject in the parts section in order to put the info in a more searchable place.
I’ve been diving into the process of cleaning and upgrading the infamous window motors and regulators for the front doors. Mine is a 74 so it is a different setup than earlier cars.
I encountered several issues (related in that earlier post) which led me to test the difference between the original e9 motors and the e28 ones. As mentioned many times elsewhere on the forum, these are the rear e28 units.
Observations so far:
- The bolts for the 74 motors are too long to use in the e28 motors. They rub against the inside of the mechanism. So you need to either use shorter bolts or add washers. DO NOT use the e9 bolts on the e28 motors!
- It looks like the reason why my driver side regulator did not mesh correctly with an e28 motor is not because of the motor gear is lower (although they are indeed slightly lower) but because my regulator frame is slightly bent. The e28 motors are less tolerant of any deviation in the frame of the regulator.
- After swapping the motors on the same regulators both on the right side and left side the difference in speed between the e28 motors and the e9 motors is actually quite significant: about seven seconds for the E9 motors and three or four seconds for the e28 motors. This is a bench test with the motors activating the regulator. So the windows are not being lifted at this point.
WTB: front driver side window motor for late 73 or 74 model
After cleaning and re greasing mine, it became a little too powerful for its own 46 year old casing and the metal shattered at two of the screws while testing. :-(
e9coupe.com
I’ve been diving into the process of cleaning and upgrading the infamous window motors and regulators for the front doors. Mine is a 74 so it is a different setup than earlier cars.
I encountered several issues (related in that earlier post) which led me to test the difference between the original e9 motors and the e28 ones. As mentioned many times elsewhere on the forum, these are the rear e28 units.
Observations so far:
- The bolts for the 74 motors are too long to use in the e28 motors. They rub against the inside of the mechanism. So you need to either use shorter bolts or add washers. DO NOT use the e9 bolts on the e28 motors!
- It looks like the reason why my driver side regulator did not mesh correctly with an e28 motor is not because of the motor gear is lower (although they are indeed slightly lower) but because my regulator frame is slightly bent. The e28 motors are less tolerant of any deviation in the frame of the regulator.
- After swapping the motors on the same regulators both on the right side and left side the difference in speed between the e28 motors and the e9 motors is actually quite significant: about seven seconds for the E9 motors and three or four seconds for the e28 motors. This is a bench test with the motors activating the regulator. So the windows are not being lifted at this point.
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