I have a W124, but it's essentially the same knob on 80s and 90s Mercedes to turn the headlights on. My question is this: If removing the knob is a matter of pulling it off, how do you keep it from popping off when you pull it to turn on the fog lamps? What secures it from popping off any time you pull it?

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Douglas
New York

The headlight knob is a snap fit. Pull hard enough that it comes off. Unless it's very old and brittle it will function properly after reinstallation.

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Fred Hoelzle

Just pressure (friction?), you pull on it a lot harder to remove it than to turn the fogs on.

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not friction, it has snap collars that lock into place, hence to take it out you need the finger strength of hercules to pull it off.

my old one was easy - hold fully out and one yank made it slide out, the new one with new switch. NO WAY - it required a rubber padded vise grips to remove.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

The knob is held by a leaf spring, there is a slot in the bottom of the knob push up with a small screw driver and it slides off the shaft. I really question the intelligance of the previous posters.

You spelled intelligence wrong.

But yes you are correct in how the knob is attached.

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nice, but in most books - it just says to pull the knob and replace with new.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

I dont know what books, the MB shop manual says depress the catch, why would they provide a slot, take a look at the knob!

On the W123, W201 and W124, I just pull out hard enough to remove the knob from it's mount.

It's a good idea to also push the turn signal switch up to get it out of the way. On the new knobs I use both hands due to the grip.

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