Booster / Fan switch removal 280SL

[Winmerc]

I am in the process of refurbishing the dashboard on my 1969 280SL, learning quite a bit about the car, I have read a number of items about the removal of the switch & thought I had done the difficult bit but still cannot get the knob off!

I made a tool to loosen the bezel nut, removed the wiring from the back of the switch & am confident that the bezel nut is now free of the thread on the switch but the knob will not come off.

I have pulled as hard as I am able, put a screwdriver behind & gently tried to lever but am not making any progress. Wondering about trying to make something to use in conjunction with a 2 or 3 legged puller.

Really appreciated any advice.

[Cees Klumper]

Hmm. I am fairly sure that when I had occasion last summer to remove this switch, after removing the nut it came free easily, so not sure what to advise. Is it possible a PO somehow glued it in? (Although why would she have). Other will chime in soon I'm sure.

[WRe]

Hi,
there is nothing behind, the switch is only fixed with the central screw/nut, see picture.
..WRe

[Winmerc]

Many thanks for advice, the photo of the switch is very clear, I did try warming the knob in case it had been glues on, I had not realised it had a rubber external layer & soon became very soft! I stopped the heat gun just in time!

Looks like it will have to be brute force & a new knob.

Many thanks, that has saved a lot of time & frustration.

Rgds,

David

[Garry]

The photo shows a flat sided shaft.  You sure the knob does not have a tiny locking screw in it that holds it to the shaft? 

[Paul & Dolly]

I do not know about the 280SL knob, but on my early 250SL, which has the illuminated version, the knob and locking ring come off "as one"

Paul

[WRe]

Hi,
there had been different switches (with and w/o light/optical fiber) but all with a central screw/nut. Sometimes the nut/thread came off if you handle it too hard.
...WRe

[scoot]

The knob and bezel come off as one.  If the bezel is unscrewed try wiggling them loose from the shaft.  I don't know of a reason that someone would glue this on.

[Winmerc]

Many thanks for your advice, it is much appreciated & great to know I can tap into so much experience. I now have the knob off & thought you would be interested t9 know why it had caused so much difficulty.

Earlier in the life of the car the knob had become detached from the bezel. Someone came up with a “fix”.

They managed to remove the face plate from the front of the knob, drilled a hole into the end of the brass spindle & used a washer & small self tapping screw & then replace the face plate. A cleaver but infuriating fix, I would have given them a bit more credit if they had drilled, tapped & used a small bolt, I have an aversion to self tapping screws.
I have ruined the knob getting to this point so now looking for a new knob!

[scoot]

I have ruined the knob getting to this point so now looking for a new knob!

That's (oddly) a very difficult knob to get.  The early style is easier.  GL!

[WRe]

Thank you for your feedback!
...WRe

[mnahon]

Here's some sources:

https://www.authenticclassics.com/Mercedes-Blower-Switch-Knob-110-111-112-113-Ch-p/auth-007575.htm

https://www.sls-hh-shop.de/main/en/mercedes-230-280sl-w113-/83-heater-system/knob-large-heater-blower-switch-reprochrome-nut-p-135073

https://classic-mercedes-parts.com/en/w113-interior/heater-blower-switch-knob-280sl-1108201592.html

[Winmerc]

Thanks for info on potential suppliers of a replacement knob, I am going to Essen towards the end of March & hope to find one there but if not will follow up on one of these.

Many thanks,