Sunroof motor repair, clean, lube

[dwcains]

Got a great used E28 motor and installed it. Even though realoem shows a different part number, the E28 and E24 motors appear identical, and the E28 motor works perfectly. Here are the two side-by-side (E24 on the left):



They both have the same number of teeth on all their gears, even though the E28 has a larger sunroof (more travel). Go figure.

My original motor had a worn gear, which seems to be the typical failure mode, so I bought this fiber gear on eBay. The new gear fits, but it's teeth are cut at the opposite angle. DON'T buy one of these, as it will jam with the motor's worm gear.



Waiting for the seller to issue a refund, but also found a few others on eBay in the EU which may work. I found both plastic and aluminum, and they appear to have straight-cut teeth, which should work wth the worm gear. I'd like to rebuild my original motor and keep it as a spare.

It's easy to take these motors apart for cleaning and lubrication. But, when you put them back together, the gears for the microswitch must be properly aligned to have the sunroof stop by itself when opening, closing, and tilting. the dots on the gears need to be aligned.



I'll update this thread if I can get one of those other gears to work properly.

[dwcains]

I should also mention that a motor from a '96 - '06 Chevrolet Cavalier looks to be a suitable donor for parts, if it comes to that. It looks like the only difference is in the gear that triggers the microswitch, and these motors are very cheap on eBay.

[635csiSyd]

I just had a main gear failure on my sunroof motor went to the wreckers and got an e34 5 series one and an e36 one was going to use the E34 one as the E36 one has a dual action micro switch and ICNBF working out what was doing what, but in saying that with some trimming of the steel cable/motor housing they both fit the later units have a motor which is about 5mm longer and slightly larger diameter and they all use the same steel drive gear.
After a bit of head scratching I worked out you can change the complete drive plate from the E24 unit onto the E34 unit retaining the micro switch, micro switch actuator cog and drive cog but using the E34 motor, worm drive and main gear which are a finer pitch tooth this also removes the need for a torque wrench to setup the preload on the drive shaft gives you a bigger more powerful motor and better gears, you need to unclip the multi plug off the E34 motor and put a 2pin plug on the power and earth wires -- I to plug into the orginal harness, the micro switch plug comes across with the drive plate, cut about 5mm out of the mounting plate where the motor sits on the long end but you will see where when you put them next to each other and bolt it all in works a treat and because it runs finer gears it seems much quieter but maybe that's just because mine was on the way out

[dwcains]

Nicely done.