300CE window regulator teeth wear

[punkinfair]

anyone have an idea why the 124 coupe - 300CE window regulators all seem to go bad, wiping out the teeth at the end of the run, up position? a friend of mine just bought one of these cars, an '88 300CE and both window regulators are bad, the passenger side especially. the teeth on the driven half-circle gear wear out and the window will not lift all the way. i searched this forum and lots of people with the same issue. the image shows typical wear, however this one is not far gone at all. on my buddy's car the teeth are completely worn off. it's almost as if there is something wrong with the mechanism and instead of stopping at the extremes of motion, the motor starts to skip on the teeth and after a while they wear to the point of not working at all.

i am going to replace the regulators on the car and i am curious if anyone has done anything when replacing the regulator to try to prevent the issue from happening again. i see there is an adjustment stop for the regulator, is this adjustment part of the issue?

also, thanks to member jt20 for the photo.