I too have done quite a few re keying of old balky lock cylinders over the years and it's really critical to clean out all the old rock hard 30 + year old grease / graphite and dirt before doing the wafer matching .

I have never yet bought new wafers, I'm sure that's the smart way to go but I just gather up some old lock cylinders and open them up , clean well and then cherry pick the very best parts .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Have you found anything to replace the fiber? felt? leather? seal ring which goes around the key cylinder (in it's nest hole in the chrome handle) and keeps some elements out?

On the several locks I've taken apart, that seal was sufficiently disintegrated to be useless and in one case actually clogged the leafs.

I've installed a rubber oring on reassembly, but that application really wants something more fuzzy.

last I checked with the MB dealer, Germany had around 14 or so new steering locks and key ignition assemblies sitting on the shelf.

Awhile back, an indy MB mechanic shared this with me; "if we don't support the mother ship (Mercedes), don't expect them to support us".

A word about W123 ignition key. A Mercedes technician told me many years ago to limit the keys on your key ring for a W123 car to one key. Multiple keys on the key ring will cause problems on the W123 ignition cylinder.

I’m drawing a blank on the “o-ring”. Maybe it is just an o-ring that has deteriorated?

If it’s not super thin, I could try cutting some out of felt or heavy construction paper on the laser. My thinking is that a drop or two of oil would give it water repellent properties. If it’s too thin, the heat from the second pass would probably destroy the clean cut on the first pass.

Get me a rough ID and OD, I’ll see what I can do.

Michael

I've used super thin Viton O-Rings in the past .

Not having more that one or two keys having off the ignition isn't just a Mercedes thing, it's common sense as most lock cylinders are made of pot metal and the weight of keys swinging back and forth is similar to operating the lock repeatedly as you're driving along ~ they wear out sooner from this have no doubt .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Not an oring originally. More like a soft seal.

Photo album: https://photos.app.goo.gl/6tBRtcjqgJ6oGqg29

If you did not notice it during your rebuild, it is probably either because it had disintegrated or maybe not replaced by someone in there before you.

Aside from a rubber oring, which is an imperfect solution IMO, another thing I will try in my next rebuild is a packing rope - a graphite impregnated & oiled packing rope, originally intended for a steam valve.

I would still prefer to find a proper felt or soft fiber ring.

Dimensions: ID: 16, OD: 20, Width: 3mm, Thickness: ~ 1.5mm

Some means of keeping the cylinder free of dust is definitely necessary, otherwise - a much shortened lifespan.

--
Michael

I agree that an O-Ring is not the ideal solution but I also feel that a one piece part is important .

You may well be onto something with a graphite infused bit of string or cord .

The originals may well have been made of leather .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Here's one cut from leather. The felt I have on hand is PET rather than wool. It melted enough that it would be a pain to get the correct dimensions. Once set up, which takes less than 5 minutes, these take 6 seconds each to cut. It does tend to fill the house with the smell of burnt leather though...

The leather one, or as many as you need, can be yours for free if in the US as it will go standard mail. I'm not sure of postage outside the US.

Michael

Attached Thumbnails

 

__________________
Usta haves '69 250/8, '76 280C, 1971 250C 114.023, 1976 450SEL 116.033
Current have, 1983 300SD 126.120

ake your screwdriver and insert it into the ignition lock cylinder. Turn it as far round in a clockwise direction that you can. Then pull the paperclip to the right as much as you can. You should then be able to slide the switch out easily.

Talk to several locksmiths, and I am sure that by the end, you will find a locksmith who will help you fix your problem. If before it was a problem to find a good locksmith, now everything is much simpler. I saw on https://www.howtobecomealocksmith.org/locksmith-salary/ that today locksmiths have a fairly high salary and that the number of people who desire to be a locksmith is increasing day by day. That's why it would be best not to fix our problems with the locks by ourselves but to ask for the help of a locksmith.

Lol found the locksmith.

__________________
1981 240D 4sp manual. Ivory White.