Howdy,
I'm hopin someone can provide some insight for me on my headlight motors. I replaced the gears and bushings in both motors about 7 years ago (brass gears, new TDS bushings). Also resoldered my headlight control module. Around 2021, the driver's side motor started spinning, not moving the headlight assembly. It stays locked in the upright position, been like that since. I took the motor out, checked everything, didn't see any issues with the internals (including bushings). A few months ago, pass side started doing the same. Just took it apart today, same story. Bushings are fine, gear is fine, and the gear meshes with the motor worm gear just fine as well. Bought a new set of bushings from TDS a few months back, when the pass side got stuck up. Put em in, followed the instructions and greased everything that needed to be greased. Now it'll lower the headlight, but won't raise it. Motor just spins until the 6 second cutoff shuts it down. I'm at a bit of a loss now for both motors, don't understand how or why they won't work right. I scoured the forums already, and all I could find was people saying to replace the bushings. Like I said, already did this, so the issue stems from elsewhere. For the pass side, the shaft that goes through the gear and cap that holds the bushings in did come out of place the 2nd time I pulled it apart (my gear got vacuumed onto the gear because I used too much grease, shaft popped out while I was bangin on it trying to get it loose). Did get it loose, cleaned the grease out, followed the instructions on another thread to lightly grease the inside of the gear/ bushings, and now it just spins without moving the assembly at all. The shaft is still affixed to the secondary piece solid, doesnt spin in the slot at all; splines still look good. I gave up for today, but I'm hoping someone here can provide some help with where to troubleshoot next. It isn't super important to have working lights, since they both stay upright and I can pass state inspection, but I would like to fix them.
Apologies for the long post, tried to pack as much info and backstory on the issue in here as I could.

 

Well, finally have an update... not sure why I originally posted this in the electronics section, since the electronic side of my headlight motors was perfectly fine. Anyways, I ended up scoring a pair of headlight motors from a '91 at the junkyard this last Saturday. Tried my luck with installing one as it came from the yard, moved the headlight, but clearly had bad bushings. Just kinda wiggled around a bit. So, I pulled the junkyard motors apart, cleaned out all the old bushing dust, swapped in my good bushings from my old motors, put it all back together (one side with the factory nylon gear, one with an aluminum gear from my old motors (not sure why I called them brass in the original post)), and BAM. Pop-ups are working perfectly again. Feels good to have two functioning pop-ups again, haven't had them both operational since about 2021.

I kept the nylon gear in one side because it was still in perfect shape, and I figured I oughta keep it in until it stops working. Still have a second aluminum gear from my old motors that I can slap in when the time comes.... driver's side assembly from the junkyard put up a bit of a fight relinquishing it's nylon gear, still not sure what it was hung up on. I had to pry the gear out of the housing as a last resort, thankfully that got it out. Gear itself had a couple chipped teeth, but that was probably a result of the prying. It was meshing with the motor worm gear just fine, made sure it wasn't stuck on that, still can't figure out why it was such a tight fit. I put it in my old driver's side housing just to keep things together, sorta "popped" into place there too, instead of just smoothly seating. Pretty interesting to me, at least; rotates just fine in the housing, not binding on anything during the rotation, meshes with the worm gear just fine. When you go to pull it out of the housing though, SOMETHING stops it. I was originally thinking that it was the metal carrier inside getting stuck in the bore on the back side of the housing, where the little peg sits, but I ruled that out since the carrier seated just fine in the new assembly with the new gear. As stated earlier, the nylon gear in question also got hung up when installed in one of my old motors.... truly, one of life's greatest mysteries.

Anyways, still have no idea why my old motors wouldn't engage the headlight gears properly, only thing I can reckon is that I got the shims put back in wrong way back in 2018 when I initially replaced the gears. The headlight motor gear replacement was one of the first jobs I ever did on a car, wouldn't shock me if I screwed it up back then... The shims in my old driver's side motor did strike me as odd as well; had 3 washers under the gear, none on the cover side. Made sure I kept good track of the shims/ washers this time around, hopefully everything works longer than 3 years this time. Very lucky that I didn't snap any of the bolts on the new motors I picked up as well, snapped a few on my old motors while taking 'em apart to harvest the bushings. Probably going to drill and tap the broken bolts and keep the old motor assemblies around as spares...

Sorta random question since I'd like to keep those old motors as semi-functional spares: assuming that the washer placement was indeed the issue with the old motors, anyone know if it'd be possible to correct the shim placement by something other than trial and error? If I'm right about the shims being wrong on my original install, then it's a bit odd that they worked for 3 and 5 years respectively before suddenly deciding they wanted to be stuck open... the old motors in question also still engaged with their respective gears just fine outside of the car, by hand, and would rotate the motor peg without issue. Installed on the actual headlight buckets in the car, they would just spin in place.

 

When doing both pop up headlight rebuilds the gear is much hard to remove from one side than the other side.

 

Gotcha, that tracks. I found it odd since the aluminum gear in that old driver's side motor came out just fine, but it has been about 8 years since I'd torn into one with stock gears. Thanks for letting me know!