300sd ignition lock help

[willw]

I've been having the key not turn in the ignition lock of my 1984 300sd problem for the last week. I can still sometimes get the key to work for a couple of days before it gets stuck again. I bought a new key from Mercedes for 17.50 hoping that that would fix the problem, but today the new key wouldn't turn the switch either. So it seems that the ignition cylinder is bad. I got the key to turn one time today and got the car home from work. At home I stopped the car with the emergency off switch under the hood, and pulled the negative battery terminal so I wouldn't have to turn the switch off. Now my big problem which I'm asking for help with is when I turn the key to the 2nd mark, or accessory position, I can get a paper clip piece of wire to go into the hole on the cylinder, but I can't get the locking shroud to release and turn. I've tried pushing REALLY hard, I've beveled the end of the wire to see it that would help lifting the catch in the shroud, I've wiggled and jiggled, but nothing works. What am I doing wrong? Am I missing a step? Is there hope I can get the cylinder out without resorting to a dremmel cutoff wheel? Thanks Willw

OK!

Success in getting the ignition lock out of the car.
Thanks for every ones help and tips in helping me solve my problem.

The final piece of the puzzle was supplied by Brian Carlton, on page 2 of this thread.
I was using a thick piece of wire to go into the hole in the cylinder. I think the wire
was actually sticking on the "dog" inside
the hole. When I switched to a tiny jewelers screw driver, much small than the hole,
I could actually feel the spring under the dog compress when I levered the screw
driver up and down! I didn't even have to use pliers to get the the protective
shroud to turn. The whole thing unscrewed easily and the whole shroud and
ignition cylinder came out so easily that I was amazed.

Brian, you are a genius! Kerry, you mentioned the jewelers screw driver earlier
but I was stuck on the idea of the wire at the time. It was Brian politely calling
me out on being stuck on the wire concept that broke through my fog :-)

With the ignition cylinder on the bench, I can feel the pins sticking as I turn
the key. Sometimes I have to move the key in and out, and jiggle it to get it to turn.
Looking into the locking mechanism that is still in the dash I don't see any broken
pieces, or any thing that looks out of place. So I'm hoping it's just the key cylinder
that has gone bad.

Until I get a new cylinder and key assembly I have the choice of either
starting the car with needle nose pliers, or removing the pins from the
cylinder and re-installing it. Removing the pins option would make the
car look like it still took a key to start it, which would be a plus.

So, any ideas on how to pull the pins? :-)

Does Peach Parts sell key cylinders that fit the VIN number, or only
the dealer?

Thanks!!!!

[nlines]

I have had some experience with this problem. If at all possible turn the key to a position where you can remove the tumbler with the paperclip. Once it is stuck you will have to disassemble the steering column and cut through the lock mounting bolts. Mercedes made these very theft proof. i think there are several threads about this problem.

[BillGrissom]

I have removed the key switch collar in both my 300D's. As I recall, one came off easy and the 2nd time took more fiddling. I recall a thin Radio Shack screwdriver worked. Once you unscrew it and look at the parts, you can't understand why it was so hard to press in the button.

Search for my post on this problem. Many times the problem is the spring detent at the rear of the switch housing, not the tumbler. The spring holder breaks off and the parts jam as you turn the switch. My son's 300D now has no spring so the key doesn't click into position, but he never reported a problem with the key self-rotating while driving. You will need to pick off the steel cover to get at that area, then stake it back and maybe backup w/ epoxy as I did.

[TX76513]

There are several threads on ingnition removal - Make sure you are viewing one that is specific for a W126 not a W123

[kerry]

I believe the dog on the locking ring is the same on the 126 and 123. Part of the issue may be in what you are trying to do. You write, 'lifting the catch in the shroud'. The paper clip isn't lifting anything. It's compressing a spring loaded dog. I found a small jeweler's screwdriver is more effective than a paper clip. Essentially, whatever instrument you use, it will sliding up a 'ramp' (the dog) and compressing the spring under the dog as it slides up the dog. Shine a flashlight on the lock to make sure you are going into the right slot. There was a recent instance in which the person had not turned the key far enough for the hole to be aligned with the dog.

[Diesel911]

If He cannot rotate the Tumbler to the Position where the Holes line up how is He going to insert Paper Clip or any other instrument into the Hole in the Tumble to depress the innards?

[kerry]

The key is turned to the correct position per his initial post.

[willw]

Well, I have the switch in the right position to get the paper clip into the
hole and it goes in much farther than the at any other spot in the rotation.
The key is right at the 2nd mark, accessory position, so I think I have that
right. I sprayed WD40 into the lock last night making sure I got some down
the little hole, and around the key. This morning the paper clip is going
deeper into the hole . But I still can't get the shroud to move by hand.
Could I use some channel lock pliers to apply preasure at this point or should
I try more wiggling/jiggling?

Thanks for all the helpful tips so far!

[kerry]

A paper clip is not rigid enough to push down the dog.

[mhin1956]

I have removed several using the wire part of a binder clip from office supplies (my desk)..bend to straight, and it helps to either file, grind or clip the end you insert into a diagonal point...

[willw]

Thanks for the tips.

I'll be trying this out this weekend.

I was hoping to do the poor mans toe-in alignment tomorrow, but with the
key sticking I'm going to put it off :-)

Will

[Diesel911]

Originally Posted by kerry

The key is turned to the correct position per his initial post.

Dazed and confused; I thought this was the Thread where the Key was broken off inside of the Lock.

[Diesel911]

Comment on the Paper Clip.

It should be a big one not the normal sized ones.

I did not even have the Normal Size Paper Clips and was able to use some Wire that is not even as stiff as a Paper Clip.

I shoved the Wire in as far as it would go without bending and took angled Needle Nose Pliers and gripped no more than 1/4" of the Wire near the lock and push it in and then took about another 1/4" Bite and repeated that.

When I turned the Tumbler I saw what looked like a hole; but, the Wire would not go in.
When I got a Flashlight I saw that it was not a hole but a Roll Pin.
I had to turn the Tumbler a little more and used the Flashlight to make sure it was a Hole I was seeing.

[willw]

From your picture #1, I have the key and the hole lined up correctly.
Your key/lock looks like a 300D, but the 300SD should be the same, I hope.

I'm not using a paper clip for the wire, what I have is a little stronger
than a paper clip but I thought saying paper clip wire was what everyone would know. The wire I'm using is thicker than a paper clip, could it be too
thick? Could it actually bind up the shroud?

Thanks again for all the great help!

[Brian Carlton]

Originally Posted by willw

From your picture #1, I have the key and the hole lined up correctly.
Your key/lock looks like a 300D, but the 300SD should be the same, I hope.

I'm not using a paper clip for the wire, what I have is a little stronger
than a paper clip but I thought saying paper clip wire was what everyone would know. The wire I'm using is thicker than a paper clip, could it be too
thick? Could it actually bind up the shroud?

Thanks again for all the great help!

As Kerry mentioned, you need to get a jewelers screwdriver. The action is not to simply stick the tool in the hole. You must compress the dog inward. Inward is defined as toward the centerline of the lock..........it is NOT toward the front of the vehicle. This is done by levering the jewelers screwdriver so that it shoves the dog inward. What also is not mentioned is the fact that you MUST hold the dog inward while simultaneously rotating the steel housing. If you let the dog go, it will catch the lock every 180 degrees of rotation of the steel housing. What is also not mentioned is the fact that you might need some 90 degree angled pliers to turn the steel housing...........your fingers might not do it. What is also not mentioned is the fact that these 90 degree angled pliers will scratch the hell out of the nice painted surface of the steel housing unless you tape it very well prior to the attempt.