For several months, I have been ordering my fast food by opening the door. For quite some time the driver's window has remained stationary, even though the motor runs. I had been too lazy to take the door apart to see if it was the $5 slider problem, or the more expensive regulator problem. Since my wife may be driving this car some in the future, my motivation to find a solution was getting higher. When I saw a replacement regulator on Amazon for less than $40, I jumped.

Sure enough, once I got in there, I discovered that the welds on one of the regulator arms had broken, so the toothed arc moved without moving anything. One of the reasons I went ahead and bought the regulator was reading that this was not uncommon, since the driver's window is the most used window on the car. Yay! I guessed right!

I didn't take any pictures, because my phone was charging, but here is what I learned in the process.

1. Getting the door panel off was harder than I expected. There are a lot of plastic hooks that fit into the door. Not knowing where they all are makes it tough.

2. 16 year-old plastic breaks easily. I ended up JB Weld-ing a few things once I had the panel off. There were three tabs that are held by white clips that had broken. I could only fix one. The other two are just over the door speaker. I tried a couple of small screws there, but not much luck.

3. Working slowly preserved the plastic sheet. I used stencil adhesive to put it back on. The spray on stencil adhesive was pretty handy for this task. I may have skipped final tightening on a nut. When I go back in to check on it, we will see how forgiving this glue is. If the sheet does not survive the next removal, Plan B is cutting a polyethylene drop cloth to size.

4. There is more than one wrong way to put the regulator in, and try to get all the attachment sin place.

5. The inside of the door sheet metal is not flat. As tempting as it is to fit things together down where the large speaker opening is, you may not be able to. The lower slide channel has to go above that opening, and there is a lip that sticks in, making it hard to put together, then lift up.

6. Put the electric motor back on last. Once it is on the regulator, you have to use the switch to reposition anything. It worked better to be able to move things around to get all sliders in place, and put on the nut for the fixed point at the front of the rail, then lower to where I could get the motor on, and tighten down, then lift the mechanism into place to replace the five nuts.

7. Don't forget to tighten all nuts before you button it up. After I was done, and cooling off, I was thinking back though what finally worked, and I am not convinced I did final tightening on the fixed point on the front of the rail. Sigh. I attribute the loss of concentration to the length of time I was out in the sun. When I finally got everything into position, I just hurried too much.

8. 16 year-old sheet metal is still sharp. I picked up a few small nicks. I am pleased not to add any new scars. It also occurs to me that the scissor mechanism with an electric motor, and an auto-down feature could pretty easily lop a digit. I'll count avoiding this outcome as a victory.

Good luck!
Tom Lynch

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2016 E350 4matic wagon
2010 ML350 Bluetec
1995 E300D Gone, but not forgotten.