'89 Diplomat. Installing new gear and done it a few times but forgotten where this little rubber O'ring goes. Is it around the shaft that gear goes over? There is a groove there but it doesn't seem like that's where it goes when I tried it but I can't see where else it would go. Comes in the new package and I didn't see an old one when I opened things up. Maybe it was disintegrated and gone. Thanks. Larry

It looks like the old one is still on the shaft to me. That black ring below the groove you mentioned.

It does kind of look like it but there's nothing there but dirt and grease and the actual groove is below. I thought the same thing when I saw my pic.

It's been a really long time since I did one of those, I can't remember exactly where it went, but if I was able to examine everything I might be able to figure it out.

FMJ guy says in the groove supposedly to hold grease down in the gear. Seems logical but when I push gear down over shaft O-ring seemed to interfere and possibly move but it's the only logical place I can see so it's probably just crappy manufacturing of gear and fit. That's where I put it but ran out of time with jamming my arm up in the small space to mount the motor. I've been having problems with this particular one eating gears. Regulator seems fine but keeps eating these gears. Don't feel any missing teeth on regulator and don't feel any wobble. My last guess is possibly the harness was interfering with the window once I pressed on the door panel. I'm hoping that was the problem so I'm trying again and going to ensure the big wire harnesses are completely out of the way this time. It's not so much the cost of the kit, it's the PITA of reaching up in there and the fear somethings wrong with the regulator.

There are 4 different housing 1 for each window maybe something got swapped found it before I tried to install them

Does the window move smoothly and easily in the track? If not that's probably what's taking out that motor.

That's what is so confusing. It moves smoothly and normally the first approximately 10 up and downs and suddenly will not move again. No jumping around just completely stops working but I can still hear motor. Each time gear is completely eaten up (three times now). The first time I thought the gear had sat on my shelf so long (10-12 years) that it probably had gotten weak. Second time I just didn't know what so I replaced it again. The only thing I can come up with now is that big harness got in the way and stopped the window from moving and therefore ate gears, so I'm going to install new gear one more time but leave door panel loose and run the window up and down several times and see what happens. I dread drilling out rivets etc. if the regulator is bad but it doesn't seem to be that.

Idon't think there's much with the regulators to go wrong, it's usually dried up grease or the window not being adjusted properly putting more stress on the motor then it's made for.
Is it the gear going or the round roller things? They're supposed to be sacrificial but some of the newer kits I've seen they're solid which would put the stress onto the gear.

The so-called bushings? Yes, with some pressure. The other kits came with the bushings and gear already assembled.

And I agree with you on the regulator. These older ones aren't like the newer ones. Basically just a metal pair of scissors. Seems tight at the hinge point and I don't feel any teeth missing. I cleaned out old lube and re-lubed the first time around.

I think you are wise to keep looking for the cause of the breakage.. maybe there is enough internal friction on all the rubbing parts put together to wear out the gear quickly.?

On one of the 1/4 windows on our power-window '65 Satellite (when Ma Mopar raided an Imperial power motor and gearbox for the 1/4 windows for a one-year-only transition), the window sliders and guides operate smoothly, but the reproduction window whiskers were just too thick and created a lot of drag on the glass.
I foolishly let the power of the motor just overcome the drag, but it didn't take long for the gear box to break.
Lesson learned.
- Art

If wiring gets in the way odds are there would be damage visible

Sounds to me like there is binding in either the forward vertical track, the sweeps or regulator itself

Thanks for ideas. I didn't see any obvious rub on harness but thought maybe the connectors themselves stopped it entirely. They are supposed to fit into the door panel but they don't always cooperate in bending the right way to fit flush. Kind of doubt it but it's baffling me. It is possible I had guides too tight the first time but I think I left them pretty loose second and third. I'll be darn sure they are loose this time. Dew wipes/cat whiskers are Sun damaged and half missing. Need to replace when I can find some.

Speaking of crappy aftermarket stuff....I'm now wondering if these gear covers are causing binding. Looks like it fits fine at this angle but when I barely tighten the screw you get this which makes it almost impossible to get the fastening bolts started. What crappy stuff and the other ones fit crappy too so I'm going to try and find a NOS gear kit. Geez. Once simple jobs become like trying to read a space shuttle schematic thanks to crappy parts!!!

Does the cover fit if you flip it over?

No I tried that but small gear isn't exposed enough. So frustrating. I put window down, pushed guides tight to window and tightened. I only drive in nice weather anyway. Now I'll watch for NOS parts that are reasonably priced. I'm so over junk parts.

Did you try the full adjustment in the service manual? It has those guides adjusted when the glass is an inch from the bottom with the 3 track screws and the 3 glass attaching nuts loose. Then tighten everything down starting with the nuts on the glass once it's up and sealed properly on the top and rear edge (pry up and rearward on glass).

I've only gone through the adjustment after having the glass out but I have seen before where it can bind when it's not adjusted right.. 3 of my Plymouth windows bind up bad so I guess i'll figure out soon enough what works best on those.

Yes I did thanks Mike. I thought that might've been the problem after first attempt but I guess not. There did seem to be some room for glass to go up further on back side with that adjustment after first attempt and I had my fingers crossed.

Once I find NOS kit I'll go back to square one. Never thought a window gear would be quite the project. I've done a bunch of them on five or six cars now and never had a problem.