I fixed the gear teeth on my rear drivers side electric window regulator on my 300D. I have a few junkyard regulators but their teeth were worn down or they were missing a couple of teeth. Had no way of knowing at the JY because I couldn't wind the gear out of the way of the motor pinion to take a look. My current installlation was starting to slip at the top of the travel and I figured it was time to restore the gears.
Here is the repair. TIG brazed silicon bronze caps on the broken and worn teeth. I then shaped them with a disk sander on the flat sides of the gear and a dremel fitted with a cutoff wheel for the teeth. The profile isn't perfect but it is much quieter now on the previously worn sections, and on the stripped section it doesn't freewheel anymore.
I took a look around and it wasn't clear if the new regulators are available anymore. My recollection was a W116 regulator could be modded to work on the W123. But, this was way more satisfying. Enjoy the visual smorgasbord.
Broken teeth. Worn teeth.
badly worn teeth
should look like this. these guys on the end don't get used.
cleaned up worn out teeth. these are noisy. they work but they growl as the window goes up.
braze on beads of silicon bronze.
grind down the beads with a Dremel and a flap wheel on my disk grinder. Easy and fast.
Not perfect but it works well. I have a slightly growly section in the middle but I think it'll get peened down by the pinion gear over time. I didn't make a tooth gauge from paper before I cut so the profiles are not perfect...I eyeballed it. The silicon bronze is a little softer than the steel. But not by much...those MB gear teeth are soft. Very satisfying fix for the afternoon.
