I recently purchased a 1980 300SD and have been going trying to solve some oil leaks, window regulators, and changing fluids to get it into daily drive status.

This forum along with others has been able to help me find problems with various window problems I have been dealing with but one is stumping me.

I replaced all the fuses, switch is operating properly. I pulled the door panel and the motor. The worm gear is working fine but the larger gear seems to get off its track and the motor doesn't run. I push the larger gear down and reset it, but after operating the window after it going up and inch, it stops working. The larger gear that the worm gear gets off its track and binds the entire system.

The lever that runs the window up and down doesn't look to be straight with the window that is drives. In order to line it up with the window, I have to push it into place. I think this may be causing the problem. UPDATE: To amplify, I am able to "grab the window" pull it up or push it down and reset the large gear and it works for about 4-6 inches. How do I solve my issue?

Thanks!

-h

On 81-85SDs and other vehicles there are slides that go in the various tracks on the window frame.

If you have access to cars in a yard, you may just want to swap in a regulator with motor. Again, on later models anything from a 126 will work as lond as the motor and window regulator are taken as a unit.

scroll down to sliding jaw and bushing to see what I'm referring to on the 126.

1984 Mercedes-Benz 300SD Base Sedan - Panels & Doors - Page 1

here's something for the 116 (see window regulator kit.
Pelican Parts - European Automotive Parts and Accessories - Porsche • BMW • Mercedes • Volkswagen • Audi • Saab • Volvo • MINI

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

It seems like there is a missing part in the motor itself. Does anything hold in the worm gear and the large plastic gear that runs the smaller metal gear the runs the regulator?

-h

Not a 100% on this but its common for a 300cd model ,after yrs of use the motor has over comes the regulator gear ,the wear gets bad enough that youll hear the gear slip , . The motor gear is hardened steel ,the reg, galvanized.

I've had teeth chipped off on the regulator. Look up the removal procedure. You likely need a regulator. Used are cheap.

One problem common with W116 power windows is that the aluminum guide bar which the track slides up and down on gets bent and then the glass binds up solely on that. Replacing regulators and motors won't fix the problem if this is the case. You can see if you can push the glass completely up and down the track with the regulator and motor removed, but the glass base still bolted up to the slider and guide bar. If it binds up, the problem is a bent aluminum guide bar. It has to match the curve of the glass.

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1967 W110 Universal Wagon, Euro, Turbo Diesel, Tail Fins, 4 Speed Manual Column Shift, A/C
1980 W116 300SD Turbo Diesel, DB479 Walnut Brown, Sunroof, Highly Optioned, 350,000+ Miles

Is the regulator suppose to be flat? Mine looks bent and some what difficult to move. The portion that attaches to the window is difficult to reattached. I have to put some muscle behind it to get it back into place. Also the switch is broke. Maybe a constant up motion or down motion has warped the regulator? Should it move freely?

Regulators do warp. Often it is because of lack of lubrication or the aluminum guide bar already being bent. I think the regulators are supposed to be flat, but it's been a while since I've seen one because I got so tired of the power windows not working that I installed manual window regulators from a European W116.

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1967 W110 Universal Wagon, Euro, Turbo Diesel, Tail Fins, 4 Speed Manual Column Shift, A/C
1980 W116 300SD Turbo Diesel, DB479 Walnut Brown, Sunroof, Highly Optioned, 350,000+ Miles

Can I use just the regulator off a w126 and marry it up with the motor i already have?

BTW, i like the interior of your car. Mine is the Tan on Tan. Wife hates it...lol

https://www.youtube.com/watch?v=X7IL85dc1ig

My exact issue. Its bent.

I'm pretty sure only W116 regulators fit a W116, but I think that the rear regulators are the same between long and short wheelbase models. You will find that almost every part on a W116 only fits a W116, and they only made the W116 300SD for 3 years, so parts can be difficult to find. Plus, it's an "orphan" car. For example, the oil cooler is specific to the W116 300SD. Mine is leaking and fortunately I saved away two mangled ones that I am trying to straighten out. I imagine they are over $1,000 each from the dealer, there are no aftermarket suppliers, and used ones are in the $500 range.

Thanks on the compliment. I want to eventually have my seats redone in two-tone MB-tex.

The grease on the regulators resinifies. It's probably ATE Plastilube and the same stuff used on the sunroof tracks. Something like Sil-Glyde would probably work at least as well, or a synthetic graphite-based grease.

__________________
Stop paying for animal enslavement, cruelty, and slaughter. Save your health and the planet. Go vegan! I did 18 years ago. https://challenge22.com/

DON'T MESS WITH MY MERCEDES!


1967 W110 Universal Wagon, Euro, Turbo Diesel, Tail Fins, 4 Speed Manual Column Shift, A/C
1980 W116 300SD Turbo Diesel, DB479 Walnut Brown, Sunroof, Highly Optioned, 350,000+ Miles