Fixed my 300E rear window not raising final 2"
 

I removed the door panel and found the vertical cable had slack. I removed the motor/regulator, applied 12v and it mysteriously worked perfectly and the cable was tight. I reinstalled it and realized the cable bracket had rotated down which prevented the window from raising that distance. I'm not sure how it was able to slip (I'll recheck tomorrow) but after rotating the bracket up, the window was able to raise all the way up to the frame.

Plastic tang
 

is broken which permits the bracket to rotate 180 degrees. If you operate the window again it will do the same thing. Unfortunately, you will need to replace the window regualtor. Mark

x2

I see what you're saying now. The tangs are pretty flimsy and the only things keeping the metal bracket notch in the plastic square. I felt the bracket pop into the notch but it could pop out. Since the motor and cable are still good, I'm sure I can tie wrap it to stay after Dremeling notches on either side to secure it.

Poor design
 

It amazes me how poorly designed these items are and it's not just MB. I recently replaced a front window regulator on a friend's 1999 BMW 530i. IMO this regulator is even more poorly designed and of lower quality (same manufacturer as MB) that is made very difficult to replace by the location of one attachment bolt behind the window glass. Broken plastic caused the failure of this part too. It would seem that at the worst a cost neutral change to both the MB and BMW parts would make the part last the life of the vehicle and save $$$ and valuable resources.

If you are able to devise a reliable fix for the MB regulator please post it. Many 124 owners will be appreciative. Mark

That is a terrible design, that some of these are failing after only 23years on the roads. Those Mercedes Engineers (oops, I was one).

On the other hand, the plastic tape drive that Detroit uses is wonderful when it snaps first year on a cold morning.

I don't care about other faulty designs. Further, you should take a poll on this site to get a feel for how many failures occurred before 23 years. I would guess that this is at least the second replacement for the poster's vehicle. My 124 wagon failed at 10 years and my 210 wagon failed at 5 years. Of course, if I listened to MB it would be "operator error", an "isolated event", or, like the biodegradeable wiring harness issue, a "wear item" (clearly a window regulator can be considered to be this but not a 5 years). IMO most manufacturers overuse plastic and frequently make invalid cost/benefit and weight/structural integrity tradeoffs. The plastics that are used do not stand up to heat/cold cycles and IR light like good alloys do. MB was forced to change its product paradigm when Lexus began dumping its vehicles in the US for less than cost and in an effort to remain competitive made a lot of bad decisions that cost the company dearly from the mid 90's until the early 00's. Frankly, I believed if they didn't wake up MB as a brand would be history. It is good to see that they are doing better but sadly they don't lead the world in quality any longer. Mark

Tie wrap idea won't work, the metal ears are angled such that a filed notch still won't hold the tie wrap securely. Also the bottom is close to the metal track so it may wear and cut the tie.

Since this regulator has one good "tang" I'm not going to modify it. When I take the one out of my car, I plan to drill small holes on each metal ear for a small sheetmetal screw. It only has to hold the plastic to the metal piece. The vertical force is on the single metal rivet and square plastic feature.

This regulator was built for a smaller window that doesn't get much usage. The front scissor type regulator is a more sturdy design (no cable and intermediate plastic piece) but used frequently. What's curious is the single pin that I assumed was designed to rotate to facilitate regulator detachment from the window. It would be better if it had a snap-in design but it was assembled by sliding it under the tangs and then riveted. Take a look at the all metal Porsche 996/986 regulator on the right for comparison.