You guys are real lucky. Here in Canada, I had to pay over $200canadian a few years back to resolve the same problem.

Mark2590 and all.

I apologize for stirring this up yet again.

After getting completely bug-eyed reading all the information floating around out there I have several questions.

Background:

Have a 1990 300SE with broken key in the ignition.
Front half of the tumbler is broken and separated from the inner part of the tumbler.
(Unfortunately the steering lock is engaged. Luckily the steering is centered if the car needs to be towed out of the garage.)

Have a VIN matched tumbler, new keys and new black anti theft cover ring.
Can easily get a new steering lock assembly.
Have the cover ring removal wire with the tapered points.

Black plastic dash cover surrounding the black anti theft ring is removed.
The under dash cover is removed.

For the operation to remove the entire steering lock assembly I have all the correct size torx and allen bits, tools, etc. to remove the air bag, steering wheel and instrument cluster. Dremel tool and bits to grind off the locking pin on the steering lock assembly...

Questions:
1. I was very encouraged to read (Mark2590's) it is possible to remove the black ring even if the cylinder is broken with only the outer half turning.

Were some folks able to do this with 1990 W126 300SE?

I can turn it to line up the slots for the 2 and 7 o clock positions.
On our cylinder, the black press tab is only on the 2 o clock position as shown on the new cylinder.
The inside part of the cylinder is stuck in position zero with a broken key.
The steering lock is engaged.

2. If I go the route of removing the entire steering lock assembly with the steering lock engaged, I am confused about the ignition switch assembly.
After 'grinding' away or cutting off the three screw heads (?) to release the switch from the steering lock assembly, is the switch not damaged so it can be connected to a new steering lock assembly?
I am confused about the details of how the switch is connected and 'locked' onto the assembly.

If necessary I am prepared to replace the steering lock assembly along with the lock cylinder and black cover ring.

If I can manage to remove the black ring that would be ideal.
But not sure if it will be better to go ahead and replace the steering lock assembly and lock cylinder as a whole unit.

My expereince with 94 E320 wagon was that the old lock worked with graphite, then finally failed totally. Would not turn with any key or force. I had to destroy and drill out..

I cut the black cover off with a die grinder and the cylinder face fell off, cracked and worn out..Then I drilled the cylinder which is soft in the key zone, mostly brass. I just ran the 1/4 drill bit through at various angles and pulled out the fragments until the keying mechanism was gone and left only the slot which could be easily turned by screwdriver. And fortunately this also disabled the steering lock and now I can drive with a screw driver and still use the central locking.

I have a new cylinder but would prefer to just go to keyless with an after-market set up.

The supposed lock removal sequence never worked for me and I tried carefully sized welding rod and compared the new cylinder to the car to be sure I was placing the pins right, I could feel them but they would never release for me.

I believe its the bottom pin releases the lock cyl and the upper one releases the black security cover.

No you dont have to pull the steering wheel and column and the steering column lock, just drill out the center until it can be turned with a screwdriver. Took me about half hour to cut off the black cover around the lock and then an hour and a half to drill out the lock. Very messy! Broke a couple bits. (Just did this a couple days ago on return from a little journey which caused the car to be sitting and apparently the mechanism just froze up! The telltale click on removing the key was gone..as if the reset spring simply died)

Puzzler.

Thank you for replying.

After prepping for this project I unfortunately discovered there is not enough room to operate a dremel heavy duty metal cutting disc on the black anti theft cover.
This is after removing the black plastic surround.

You mentioned the die grinder bit which makes more sense for this job.
Was this used around the inside edge to enlarge the circular opening?
My tumbler has a broken key in the bottom half and the front part of the tumbler is broken away from the bottom and free spinning.

Also, ours has a decorative thin metal chrome cover over the core which I was told is no longer available. I suppose this piece is not absolutely necessary when installing the new core and anti theft cover.

Thanks again for the reply.

No doubt this point is well documented but here goes.

Although it would be nice to drill away at the lock cylinder core to gradually chip away and remove the bits - this without disturbing the black anti theft cover - the clever MB engineers made this very difficult if the front half of the cylinder is broken free from the bottom half. The front half would just spin with the bit unless somehow it is held in place for the bit to be able to grind away at the metal.

I will do more poring over mountains of info posted on this topic.

Thank you!

Sure, W126...

Mine is a 94 E320 and the dash may be a bit different. The black trim comes off easily, its snapped in and held with velcro on one end. Then the lower dash panel is removed with a few hex screws and phillips. In my car you can cut the black security cover off about a quarter inch back from the round collar around the lock. My lock like most was already broken between the key slot at the face and the inner mechanism which drilled out rather easily. This easy drilling is in contrast to the main barrel of the lock which is pretty tough steel but can be drilled.

Hmm the front half just spin..I suppose it would but the front part..(Not nearly half but about 1/4 inch) mine just fell off once the black ring was cut off. Its a separate face piece and appears attached with a drift pin on my new lock. This front half (about a quarter inch thick) might be easily snapped off with a screwdriver or chistle, but if yours is free to spin I believe its also detached from the main cylinder like mine was. In that case it will fall on the floor once the black sleeve is removed.

Let us know!

Happy to chat in person if its needed to assist..

Thank you Puzzler.

Just to cover all bases went ahead and ordered the steering lock assembly and I will be able to get acquainted with the locking setup with the new black ring and tumbler.
It will be here next week and I will be able to go with plan B if cutting away at the black ring runs into overtime.

After talking to a friend about die grinding I have a question.
Were you using an air powered tool for the die grinding bit?
I understand the bits require high rpm to be effective.
None of my battery powered or AC drills will reach the speed an air tool can provide.
I need to check the specs on the Dremel.
Still having a difficult time picturing being able to cut around the black ring on the outside as you mentioned.
Only one way for me to find out.

The car is an hour away and parked front first in a garage.
Can't go there as often as I would like and have to make sure to have everything needed.
I do have the option to get it towed here and contacted a reputable towing company and worked out the details just in case.
Unfortunately it will need to be towed with a regular truck with the rear end lifted and rolling on the locked and centered front wheels.
I was assured this would not be a problem.

W126..

My grinder was a chicago tools long neck die grinder, 25,000 rpm 4 amp motor... with cut-off bit in the chuck to hold the cut off wheel. I used a wheel..Checking, 3 inch cut off wheel, 40 grit. I bought a stack of wheels but needed only one, the steel cut easily. A smaller wheel would have been easier to get into the space.

I did leave one tiny nick on the wood veneer above the lock. Also cracked the finish in one spot trying to pry it off so I just left in place. One might shield the surrounding interior parts with something substantial..

It was easy to cut from below but on the top side of my 94 the veneer was too close to get a clear cut and I needed to use the grinder sideways, if that makes sense..just eating away the steel edge on..sparks flying but they did not damage the plastic or wood. Use eye protection!

I basically just chewed the black steel cover back until it left a straight line for the lock face to drop out and then began drilling out the center.

Im still trying to use the pin through the slot on the lock barrel to get the retaining clips to release..Maybe with drilling and more access they will release and I can install my new lock cylinder and replace the metal security cover..Or maybe just go with an aftermarket keyless push button. Meanwhile driving with screwdriver..

Yeah, you need a comfortable place to do an involved job with power and rest, cleanup tools and if needed, media nearby to review for questions. Good luck!

Here is an update and thank you for replying.

After feeling encouraged by Mark2590's report, made another attempt at the lock cylinder.
Unfortunately I was mistaken in thinking the front half of the cylinder is broken free to rotate freely. It is turning but not far enough to line up with #1 mark. Tool does insert and catches the black spring but not deep enough to release the black ring.
The black ring has a slight wiggle and I can tell it is held on with something. With the tool inserted it tightens up.
Anyway, tried to completely break/separate the front half using a screwdriver/vice grip but not getting enough grab to exert any force on it.
The holes are less then 1/4" away from lining up and would like to get to that point and attempt the ring removal before moving on to the more extensive operation.

One way or another the cleanest and most expedient process will be to go ahead and remove the replace the lock assembly, core and black ring, all which I have.
If I can somehow drill away the front half of the cylinder without disturbing the black ring and make another attempt at duplicating Mark2590's success that would be nice.

For accessing and removing the steering lock assembly:
After removing the knee pad under the dash I am facing a black metal corrugated duct across and under the steering column.
Most likely due to me using the wrong jargon I haven't had any luck finding info on this piece.
I can see several screw heads on the left side which appear to hold it to the door opening with the vent that supplies air the to door glass defog grill.
Will removing these screws help swing this black pipe away and off the other end at the center console?
I need to get a closer look with a good light to see how the right side is held on.
Removing this metal tube will be necessary for lowering the steering column and accessing the steering lock assembly.

Many reported being able to remove the lock assembly without removing the steering wheel.
Just for the exercise removed the airbag and saw the infamous #10 allen screw holding down the steering wheel.

Each attempt at this involves an hour each way for a visit to an elderly relative so it's been slow going.

Another update:
Found good info with pictures on how to remove the black corrugated metal tube under the steering column if anybody else runs into this thing.

Removal and Replacement of Expansion Valve

Rather than using a screwdriver to twist the faceplate covering the key cylinder I made a tool by grinding down a bolt that had a shank big enough to emulate a very stubby key.


The dimensions of the rectangular stub are taken off a key, about 9mm by 3mm, and the stub length inserting into the keyhole is about 3mm. You want it to be deep enough to catch the faceplate, but not the cylinder behind it.


This bolt has 3/4" wrench size head... it was a super easy turn with a 3/4" wrench on this "key nut tool" to shear the tiny pin that keeps the faceplate oriented on the cylinder. One of those cases where it takes more than an hour to make a tool that you use for literally 3 seconds and you're done.

Attached Thumbnails

 

__________________
Cheers!
Scott McPhee

1987 300D