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Window regulator for passenger side?

Started by Alan.smith1800, 30 November 2013, 10:17 PM


Well, I tore into the drivers side today and replaced the regulator. Sure enough, the regulator had a snapped off corner and was terribly warped. Thankfully, the motor and switch was fine. I can now go thru a drive thru with a little more respect.

Now for the passenger side...

I have not diagnosed the problem yet. Could be the motor, the switch or the regulator. I'm betting on the latter, but the part is almost $400! Any one know why the passenger side is so much more than the drivers? I assume they are mirror images of each other but I could be wrong...


Hi.  I have replaced or overhauled all 4 of mine.  Awkward jobs.  The ones that are used less are less likely to be warped, but are more likely to be just jammed. The grease is ancient and the slides/runners for the glass is sticky.  I suggest you take it all out and give it a good clean before you buy new ones. There is no real way to repair a warped backing plate, so don't waste time on even trying. I had success with one second-hand one, but they are rare. Good luck.
Sydney, Australia


I couldn't agree more. The previous owner had drill holes in the door sheet metal to help reach the 5 mm hex bolts that hold the motor in place. The swap out took me 2 hours... 30 minutes out and 1.5 hours to get it all back together. The passenger side window is currently held up with sticks of lumber! I haven't looked inside the rear doors yet. Are the rear regulators the same as the front door units?


and the sad part of the story is...........I have good regulators inside a parts car which is probably going to the crusher in the next few days.
Its a pity we're so far apart.  Would love to help


The rear regulators are completely different.  And they come in two flavours: short and long wheelbase versions.
Sydney, Australia


Hello - 1977 450 SEL - trying to remove the right front (passenger) side window regulator.  Read that you have to remove the motor first to get it past the window rail and if there aren't access holes, you have to drill them.  No access holes on mine, and this does not seem very MB engineering to have to drill holes.  How did they get it in there in the first place?  Maybe they install the window and guide rails after?  Thought this would be fairly straightforward but I'm stuck. Any help appreciated.


I have not had to deal with the doors you have to drill holes.  I usually wind window about half way down, unbolt regulator and disconnect bar from bottom of glass, shove glass up and regulator out of the door hole.  Note that the 3 screws holding the motor to reg are not the same length. Be sure to put back same or the longer bolt will hit things and make it not work.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'21 E450 Cabrio


Well I figured it out.  Great YouTube videos from Michael the Mercedes Guy were invaluable. Turns out I did have to drill holes and found that the 3 bolts holding the motor to the regulator frame were hex, so I had to make the holes pretty big to get a socket on them. The holes don't have to be in the exact location because you can unbolt the regulator frame from the door and move it around a bit to line up the bolts with the holes. Replaced the bolts with slightly longer cap screws which made the reassembly process easier. Window now working!