Window only goes up quarter of the way.
 

http://www.peachparts.com/shopforum/diesel-discussion/167113-window-doesnt-go-up-stuck.html

I POst my problems in the diesel forum. But I would like some help here as well.

My windows goes very smoothly up and down but only quarter of the way up, then the sound of machine guns starts. Where should I start to pull the inner of the door apart ? Thanks.

This is an S class W140 body.

Sounds like a stripped regulator to me. Check eBay or your local junkyards for the part. I'm not sure if the W140 can be remedied by the $7 sliding jaw like the W126 can...

Answer:
 

Inner Door Panel Removal DIY Links
http://www.peachparts.com/shopforum/diy-links-parts-category/150747-inner-door-panel-removal-diy-links.html

PART NUMBER SEARCH RESULTS WITH PRICES
Vehicle 1992 Mercedes Benz 300SD
Part: Window Regulator Rivet
O3043-61962 Window Regulator Rivet IN STOCK $0.49

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1WW02D0M91X412F0IE&year=1992&make=MB&model=300-SD-003&category=All&part=Window+Regulator+Rivet


Vehicle: 1992 Mercedes Benz 300SD
Part: Window Regulator
Select one of the products from below
---------------------------------------
Window Regulator
Front - Left
without motor
Prior to listed chassis cut-off requires (4) 003 990 24 97 rivet. Chassis: A 331384-
------------------------------------------
Window Regulator
Front - Right
without motor
Prior to listed chassis cut-off requires (4) 003 990 24 97 rivet. Chassis: A 331384-
---------------------------------------

Window Regulator
Rear - Left
without motor
Requires (5) 003 990 24 97 rivet for installation.
---------------------------------------

Window Regulator
Rear - Right
without motor
Requires (5) 003 990 24 97 rivet for installation.

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1WW02D0M91X412F0IE&year=1992&make=MB&model=300-SD-003&category=All&part=Window+Regulator


http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=140134&M=603%2E971&GA=722%2E367&CT=F&cat=19B&SID=72&SGR=045&SGN=03

watch for motor wear, too
 

The "rack" that the front door window motor gears work against is visible as you roll the window up and down. If there's a problem with this gear, you should be able to see it plain as day. If you don't see an obvious missing tooth or severely worn tooth, check the motor itself.

I went through the effort and cost of replacing both rear regulators in my '92 300SE, only to find it was the motors that were the problem.

To test, disconnect the motor from the door, leaving it plugged in. Grab the gear with a pair of pliers - not too hard as to damage the gear, but hard enough to hold tight and not let the gear slip in the pliers. Hold the body of the motor with your free hand - hold on tight. Have a friend bump the window switch up or down and see what happens. Be ready for some serious torque with this test. On my rear motors, the driver's side would work fine on the downward path, but I'd get a pop-pop-pop on the upward path. Rebuilt motor - no more problems.