Replacing the window regulator.

[Boudreaux]

The drivers side window regulator of my '94 SL500 is beginning to have a lot of play and drops when all the way down inside the door. Is it difficult to replace after removing the door panels, etc.

Any help would be appreciated.

[kip Foss]

Widow regulators are natoriously difficult to remove and replace. I say this from a fair amount of experience, but you may be a piece of cake. I have never worked on a car as new as yours.

You may not have to actually remove the scissor mechanism. It might be just a loose bolt or some such. With some cars that I have worked on you have to remove the window out the top of the door. This means taking off the seals on both sides and sometimes removing the metal frame that clamps the window glass to the window.

On one car I actually cut out one of the inner door frames out, tood the regulator apart from the motor and window, winkled the motor out and then got the regualtor out. Not a lot of fun but I figured it was easier and safer that farting about with the window. When I was finished I ran the window up and tack welded the brace back in.

When I remove door panels I use a thin flat prybar called a Wunderbar. Slide it gently under the panel and along until you feel it hit one of the little fasteners. Then just turn it sideways and pop the fasteners out. Be gentle because the panels are made of pressed board and will not take a lot of rough handling. If you loose or damage a fastener they are usually sold at the local parts shop on one of those 'Help' racks.

Good luck

[jim16671836]

In the 80's MB went to a L shaped clip that holds the door panel on...you need to find out if your car has the L shaped clip and if it does you will need to raise the door panel up and not out...when those L shaped clips break off their is no repair except double sided tape....the kind of tape that is used on some box trailers and it works...Kipp does know the older SL's and SLC's and he might be right about the newer model..I have broke the L shape clips off of a door panel on a 126...The 123's also have the male to female clips...Jim

[kip Foss]

James is right about the clips. The only kind I have dealt with in my older MBs are the metal or plastic pop-ins.

[Boudreaux]

Bump for a '94 SL500 window regulator DIY

[fcicco]

I did my 95 SL500 window regulator last weekend. It is not hard to remove the regulator. It is a pain to tear down the door panel. I followed the instructions from All Data.
Once the door panel is removed, raise the window about 2" - there are three 10 mm bolts clamping the window to a rail. Remove them. Raise the window to full closed position and clamp in place making sure that the clamps don't break the window. Lower the mechanism (window should remain up). Drill out the rivets and remove two screws holding the rail. The whole assembly will come out (motor and all).
My problem was that the rivet holes were elongated from wear. I replaced the regulator anyway after drilling the holes to the next size. Drilled and tapped the regulator for oversized bolts - lock tight and lock washers. Good lube and adjustment - works great.
When I was done, I disconnected then reconnected the battery to get the window Hall sensors and soft top sychronized.
Job took all of a Sat. afternoon

[tecqboy]

I believe that your 94 has the same arrangement as my 91.

To remove door panel 1991 300SL.


1. Carefully remove the door lock knob by pulling outward ( parallel ) to release.
2. Using extreme care, remove the wood trim behind the door release handle by lifting outward with a panel removal tool.
3. Extract the single screw securing the metal trim behind the door release handle.
4. Remove the single 10mm bolt securing the door latch assembly to the door.
5. Carefully remove the seat control assembly and wood trim on the door panel using a panel removal tool and prying outward on the outside edge.
6. Remove 1 screw from inside the door pocket on the outside edge of the door in the pocket hinge assembly.
7. Remove the single very small screw from inside the pocket on the inside edge of the pocket securing a piece of plastic molding. Remove the molding and extract 1 large screw securing the door pull handle and panel to the door.
8. Extract 1 screw securing the black trim piece around the door latch. Lift up from the bottom to remove.
9. Extract 3 small screws securing the chrome trim on the top of the outside edge of the door panel and remove trim.
10. Remove the courtesy lamp assembly at the bottom of the door panel by snapping it out with a panel removal tool.
11. Using a panel removal tool, carefully release the “pop” fasteners from around the perimeter of the door panel. Lift up on the door panel to release the metal clips from the top edge of the door panel.
12. Slide off the vacuum hoses from the connectors near the panel bottom.
13. You are now holding the free door panel.

Reverse steps for installation.

[Dee8go]

I believe the regulators on my back windows are bad, and would like to replace them. Now I'm wondering if I'm up to the task. Has anyone replaced the ones on a 1984 300TD? It doesn't seem like these would vary that much from model to model.

[jim16671836]

I think the regulaors on any 123 are fairly easy to replace... The Door panel pops straight out... do not lift... you will need to remove the black plastic piece that is inside the chrome door opener... then remove the small screw in the door opener, then pull the chrome piece down over the door pull and you will see a larger screw, remove it and 2 more large screws that hold the door pull in place, then remove 2 small (all the screws so far are philips, you will need a large headed philips and a small headed philips) screws neer the door lock... now pop off the panel easily and slowing with a couple of flat screwdrivers. you will need to raise the panel when it has been poped loose on both ends and the bottom.. then disconnect the light at the bottom ..
you will need a 10mm socket and maybe a open end/box end... Remove all bolts and nuts except for the one that holds the door stop in place... you can try lowering the window before disconnecting the wires. it is easier to remove the 2 bolts that hold the glass channel to the regulator with the glass lowered... disconnect the wires to the motor, anyhow remove those 2 bolts and then raise the glass to the top so that it is out of the regulators way... you can hold the glass in place with 2 small screwdrivers or wedges..

[jim16671836]

Back door bent regulators are the norm in the 123 series if you have power windows, which you do. It is hard to find good used back regulators... I have straightened some of them but in the future do not run the windows all the way up tight but rather let them down 1/4 inch.. if you need any assistance just give me a call.. 812-897-0667 Jim Harris