Door lock trim repair W124 and others DIY

[Jeremy5848]

The driver's door exterior lock on my 1987 300DT (W124) came with missing trim -- the round stainless piece that the key goes into -- probably because someone had tried to jimmy the lock.

The trim piece itself isn't available separately, of course. I checked with the dealer -- $600+ for the entire lock assembly! Fortunately, I was able to find a used one but the problem of installation still faced me. Would it be possible to remove the trim piece and move it to my door without damaging it? It is, and here's a DIY. It's written for my 124 car but probably works for many other Mercedes exterior door locks.

Note: It's advisable to do this operation over something that will catch any tiny dropped parts. It helps to have patience, bright light, good eyes, and small hands.

Removing the stainless trim piece (see first photo) turned out to be fairly easy. The piece is held on by friction and can be slowly levered off with a screwdriver in the key slot. Work a little on one side and then the other, trying not to bend the metal too much, until it pops off. Behind the trim piece are a little "door" and a pair of springs on a pin. These parts are shown in the second picture.

Putting the parts in your lock is a bit of a challenge. It helps to have a second person for the last step.

First, put the springs on their pin and put the pin in its slot in the lock (see the third picture). Next, put the little "door" piece in its slot, making sure one end of each spring is under the door (see the fourth picture -- the springs aren't right but I couldn't take the photo otherwise).

Once the door is in place with the springs, it's under tension. You have to hold door while putting on the cover. I used a popsickle stick with one end cut flat. (The end of the stick was slippery, I should have put something sticky on it.)

With the stick holding the door and springs in place, I slipped the cover over the stick (it fits through the hole in the cover nicely) and slid it down into place. Then my dear, sweet wife started to press the cover -- oops, the stick slipped.

Try again. Springs, door, stick, cover, oops. Finally, about the fourth time, the cover popped into place and nothing slipped. Finished.

Jeremy