W123-TECH Broken or Seized Ignition Lock

[shadetree]

Last evening I parked my 84 W-123 230E sedan in my garage.
Today when I attempted to start the vehicle I cannot turn the
ignition even to the first position. So I figure either the switch or
the steering lock or both have gone south for good. I have on
previous occasions used WD-40 to get the switch to work more
freely.
I have 2 Haynes manuals. Number 697 for the US spec. 84
300Dturbo that I also have had since 84.
I also have Haynes manual #677 I bought in Europe several
years ago that pertains to the250 & 280 models76-84.
I use this manual mostly for reference to things in the 230E
except for the engine and power train. (use a US spec 84
190E Haynes manual for that).
Anyway references in both manuals are about the same
for the Ignition switch and steering lock.
My question at this time is this: In both manuals instruction are
to turn the switch to position 1 and then insert a wire in the
locking cylinder cutout.

Since I cannot turn the switch to position 1, what should I do?
Any advice will be really appreciated for sure.
Regards,
Chas Mattix

[Robby Ackerman]

Charles

These switches go bad with little or no warning. I've tried WD40 on other cars and get another year or so from a switch, but was never succesful doing this with my 123s. Like you my experience was the key wouldn't turn and I had the car towed the 15 minute drive to my MB dealer and had them replace it. Seems like it cost me around $350. I'm sure someone on the Forum can tell you how to DIY.

Cheers,

Robby

[bill streep]

Sorry to hear of your problem... I've had them replaced on both my W124 and W202. The W124 required about 3 hours of air chisel time... In my case, the W124 was a broken steering lock - and no amount of fiddling with it would have worked. I've heard some folks have had success with the following technique:

Put the key in the ignition, and put some vice-grips on it. Take a vibrating tool like a sander, and put a piece of wood under the key and try and transmit the vibrations up to the key. Then try turning the key repeatedly. IF you are lucky, you'll get the broken pin to vibrate up in place long enough to get the key to position 1. THEN and only then can you remove the tumbler. I've heard of folks trying for an hour, and it worked... Some less, others not at all.

[shadetree]

Well, today I gave up the ghost and had the car transported to
a repair shop I have great confidence in. This was after trying
several procedures many recommended to try and get the
ignition switch to turn to position #1. None worked so think the
switch had gone all the way South.
In hind sight I think I should have heeded the advice provided
during the mid-1990's by our past MBNA Club Technical Director,
Mr. Frank King. That being to just have the switch replaced
after long use before it fails.
Best regards,
Chas. Mattix
84 300Dturbo
83 230E
93 BMW 318i
99 Subaru Forester
88 VW Jetta

[Grey Ghost]

Mr. Shady Tree has it right...this cylinder MUST be replaced prior to its failure...it's much cheaper to do it that way

123 owners: as soon as you feel too much play in the ignition cylinder, get that thing replaced before it strands you!

[bluexr4]

On my newly acquired 300D, the ignition switch doesn't turn anymore. The 2 keys are copies & badly worn & I think things just don't match anymore. When I first got it home it was tricky to get to turn. The switch seems real sloppy also. I really need to drive it though, it's my new winter car & snow tires are on the way from Tirerack. Where can I get another switch/key? I hate to do this but if I'm going to replace the switch anyway can I force the lock to turn with a screw driver without damaging anything else? I can't find the procedure on removal of the switch on the dvd, but I'll keep looking.

[mercedessd]

On my newly acquired 300D, the ignition switch doesn't turn anymore. The 2 keys are copies & badly worn & I think things just don't match anymore. When I first got it home it was tricky to get to turn. The switch seems real sloppy also. I really need to drive it though, it's my new winter car & snow tires are on the way from Tirerack. Where can I get another switch/key? I hate to do this but if I'm going to replace the switch anyway can I force the lock to turn with a screw driver without damaging anything else? I can't find the procedure on removal of the switch on the dvd, but I'll keep looking.


chances are the brass from the copies have accumulted in the lock. the original keys are steel and do not cause this problem, you will likely need to drill the lock assy retaining pin and remove the entire lock assy and replace it. depending on your abbilities, this could be a very tough and costly repair. if i were you i would order a new steel key from mercedes and with brake cleaner and compressed air, use a computer duster is you do not have acess to an air compressor. first flush the lock cylinder and try to remove all the brass debris then use the air to dry it
try it only with the new key from mercedes, they can get you a new key that is matched to your vin, the only way this will not work is if the lock is not coded to the car. i doubt you could get it to turn with force, but if you were able something would be destroyed, the steering lock would likely not retract.

[Robby Ackerman]

There is a web link in this forum for the procedure for changing the ignition switch. If no one else posts it, I'll see if I can find it. The switches wear out and you can order a new one from your MB dealer. They will want your VIN and likely some sort of proof of ownership. The new switch will be keyed to match your door locks so you need only one key to work everything.

When mine seized I had the car towed to my dealer, he put in a temp switch until the new unit arrived, I drove home, and forgot to take it back. About two years later their loaner switch started sticking and I took the car back and they put in the switch with the matching key.

[mercedessd]

There is a web link in this forum for the procedure for changing the ignition switch. If no one else posts it, I'll see if I can find it. The switches wear out and you can order a new one from your MB dealer. They will want your VIN and likely some sort of proof of ownership. The new switch will be keyed to match your door locks so you need only one key to work everything.

When mine seized I had the car towed to my dealer, he put in a temp switch until the new unit arrived, I drove home, and forgot to take it back. About two years later their loaner switch started sticking and I took the car back and they put in the switch with the matching key.


the main problem is if the key will not turn the ignition tumbler cannot be easily removed, at our shop what we do is drill the locking pin (circled below) i have heard of people smashing it with a hammer and punch, doing this unfortunately ruins the assy.
you will need the parts below:
lock assy (usually comes with ignition switch)
lock tumbler assy
black metal collar around the tumbler

normally when the key turns you put it in position 2 and using a tool you can push the pin i circled in and remove the entire assembly with ease after releasing the 10mm bolt on the steering collar at the lock. hope this helps

[Grey Ghost]

speed is of the essence in getting that assembly replaced. if it locks on you, it's a MAJOR mess to swap out!!

[shadetree]

I suggest that if you do get the switch turned on to start the car and
drive to the nearest MB repair facility and don't turn the switch off until
it is replaced with another switch. Most MB repair facilities will have an
extra to use until you can have a new one installed.
Regards,
Chas Mattix

[porkpie]

I have a new ingnition switch from the dealer to match my VIN#. My problem is that the switch is so worn out now that I cannot get the key to turn to ANY position. How will I or anyone else be able to get the new switch in?

Thanks

[VLayton]

The release button (silver) normally needs to be pressed in to release the lock assembly. If you can't open yours, the button will need to be drilled out fully. I had to drop the steering colum a bit to access when I faced this.

[Sokoloff]

I'd try REALLY hard to get the key to move. Try turning the steering wheel hard while turning the key. Might even try to take the load off of the front wheels while turning the wheels and the key. It will be worth your while if you can get it turn and not have to resort to drilling it out. If you do get it to turn, leave it there until you remove the cylinder.

Len

[Maxbumpo]

Here are the tricks I've heard:

Jack up front end so that front tires are hanging; this takes as much load as possible off the steering lock.

Order a new key from MB that matches the VIN (and theoretically the lock cylinder in the ignition). If you have ordered a new cylinder, it should have come with a new key.

Remove the plastic cover from key and grip with vice grips

Shoot some MB lubricant into the lock

Insert key/wrench, and apply some vibration to the key with something like an orbital sander.

Gently try to work key while simultaneously vibrating and turn the steering wheel.

Be very carefull to not break off the key in the lock. Once you get it turned, you must progress to removing the lock cylinder.

Let us know how it turns out!

Question: did the lock give you any warning signs in the preceeding weeks/months that it was about to fail? Do you have a large and heavy key ring?

[porkpie]

After trying for over an hour, I left and locked the car up. I got the new cylinder from the dealer with a key and had my mechanic start to work on it. He sits in the car turns the key and the car starts. You can imagine what I said. Anyway, they got it out, the new one in and I'm running again. Now on to the drive shaft that's vibrating. Fortunately when you buy a MB from this mechanic he give a year warranty on everything but oil, brakes and tires so I'm set.

Thanks guys.

[Maxbumpo]

LOL! Glad to hear it was a happy and simple ending.

I'm still curious - did the lock give any warning signs? Do you have a heavy key ring (more than just a couple keys)??

[porkpie]

I've only a few keys. It was catching a few times the previous week and then just locked.

[Grey Ghost]

it's my understanding that drilling the old cylinder out is a MAJOR PITA

You're lucky, PorkPie

p.s. have you christened that character-laden vehicle with a proper name yet?

[porkpie]

I've never named a car. I think Angus will do though...

[VLayton]

Angus? Why on earth?.... She you're quality cow? :rolleyes:

Steady heffer? :confused:

Kinda unflattering methinks :(

but hey, that's just my opinion... :o

[porkpie]

It'a a boy, not a girl for me. Angus after Angus Young, the real deal (guitarist for AC/DC)

[oxfordlane]

I just purchased a 1979 300D which hasn't been cranked in 3 years and had to have a key made through a MB dealer using the VIN. I got the square key. It works in all locks and the trunk, but won't budge the ignition. I've tried shaking the wheel and wiggling the key at the same time......sprayed lube into the key hole, put the car in neutral, but nothing seems to work. The GOOD: car looks great, has 130K miles on odometer, has all origional manuals with stamps up to 85K, untouched first aid kit. The BAD: car's manual sunroof handle was not turned that 1/2 crank to seal it, so it has leaked for the 3 years. The UGLY: took 3 days to dry out after pulling front seats and carpet out (but all wiring looks OK), key won't turn at all. Any suggestions?

[Robby Ackerman]

Could be that a former owner had an indy shop replace the igniton switch and didn't know or wasn't willing to pay for a dealer supplied switch & key, which would have matched the doors, trunk & glove box.

[oxfordlane]

I was worried about that. I can feel 'play' in the key when I attempt to turn the steering wheel from side to side, but I saw evidence of someone 'monkeying' around under there. How hard is it to remove the ignition switch? Does the dashboard have to be removed?

[Robby Ackerman]

There is a remote starter terminal -- the small rectangular box near the battery. You'll still need to activate the glow plugs.

[Robby Ackerman]

It isn't difficult, and no the dash doesn't need to be removed. You just need to know "how to," ha. Do a search, I'm sure it has been detailed in this or other forums. Also, the 123 repair manual is available from the MB Classic Center on CD for $20 - $30 or so. Their main phone number is 949 598-4850, and the parts advisor is Woody.

[oxfordlane]

Thanks, I appreciate the info. I will order that manual. I've just spent the last 3 hours removing pine tree tar from the trunk, roof, and hood (3 years worth!).

[oxfordlane]

How do you activate the glow plugs?

[cervan]

to do that you have to turn the key to position "2" on the key in american and japanaeese cars its "acc" or accesorys that trips the relay to heat them up then you start the car and they go off. if your car is the one with the pull knob then pull it and then the glowplugs will light unless you have a bad one. then nothing ill happen because they are parralell meaning one thing goes out then you have no circuit. they have conversion kits and stuff i would be so happy to work on your car.

[oxfordlane]

Not being able to turn the key makes that impossible. Is there a way to do so without being able to do that, maybe under the hood. I also need instructions for replacing the ignition switch......the link given (sometime in the WAY past) will not work. I put a new battery in the car, and the lights work with the buzzer driving you crazy!! So I am eager to get this car cranked up and on the road.

[VLayton]

Today's repair order was just this very thing!

In your situation, I would get a new ignition assembly, tumbler and keys. It's going to be a lot of work so you might as well pay to start fresh. Gambling on a used lock could put you back in the same situation at any time.

[VLayton]

The assembly is going to have to be sacraficed, because it doesn't disassemble properly without the key turning action.

[VLayton]

This is a 1983 model, hopefully your 1979 doesn't have this rotating key that spins inside the electrical plug. The key is needed to turn this to the proper position. (The oil came from the owner's desperate attempts to get the key to turn one more time)

[VLayton]

The trick to simply replacing the tumbler is removing the black collar. (A)

But since you will have to drill out release button (B) it's not worth messing with the collar you don't have a key for, unless you have the issue mentioned in post twelve. I believe this action disables the unit. You may need to reuse items (C) mircobuzzer switch and (D) vacuum control shut-down switch.

[VLayton]

Because the owner was able to get the key to turn ONE LAST TIME (ongoing symptom for months, apparently) I was able to save the assembly and install a new tumbler assembly.

[Robby Ackerman]

Attached are to two files from the service manual. See if one or the other is of any help.

They wouldn't upload since they are over 2 MB in size. Private message me with your email address, and I'll email them to you.

[oxfordlane]

Thank you all so much for the information. I got it (the ignition lock) out today (Sunday) and will order one tomorrow for that VIN. I can tell it was changed out at some point in the past.....the paint around some of the nuts was scraped off with a ratchet before I got mine in there. I also picked up a service manual today and fixed one of the exterior door handles in less than 10 minutes. These cars are really well made!

[VLayton]

Well, an ugly update: Turns out there IS a lock assembly problem. It worked fine several times, and after all the prescribed service I moved the car to vacuum it, and the steering lock engaged and, yes would not unlock. :mad:

There was no way to confirm this without the whole system being reinstalled, it seemed fine while out. I managed to get it open after a while, but still back at square one. The upside is the tumbler is probably good and the keys won't be mis-matched.

[oxfordlane]

My situation is worse........I got the lock assembly out and called the Mercedes repair shop that ordered me a key. He was really cool and told me to stop by and borrow one that he had in the shop just to see what the car would do (I haven't been able to crank it since I bought it). The car would turn over, but not crank up. Oil leaked from the block in a big way! Gonna have to get a motor. What should I look for?

On the bright side.........all of the windows work, the lights and blinkers work, the antenna is broken, but the old factory Becker radio actually sounds good.

[VLayton]

Well we have a new MB ignition lock on order... :rolleyes:

Don't dismiss the old motor yet! A number of simple things could be the issue.

Bad glow plugs? Blown glow fuse? Clogged/gelled fuel filters? Valve adjustment?
Seized belt-driven accessory? See how it turns by hand...check the timing chain.

[oxfordlane]

Thanks for the info. Could any of these cause oil to leak from the front of the engine?

[Robby Ackerman]

Check the oil lines running to the oil cooler, which is to the left of the radiator. When they get old they break/leak big time.

Another oil leak source is the air filter. It has an oil drain and the return to the sump is often misaligned and oil will pool under the car when it is parked.

[burntcloth]

I just finished replacing the ignition lock tumbler unit in my W123. (82 300TD) I don't see very clear instructions here, so I'm going to add them (this is assuming you can still turn the key!):

The tumbler I installed looked exactly like the photo in post #36 of this thread. It has one hole to access the "lock button" you can see on the outside of the tumbler. Later models have two holes and you need a different custom-made tool, and probably different directions.

1. Pry off silver decorative ring around lock assembly.

2. Look at the new tumbler: see how you turn it to a certain position and you can see a small hole? That lets you access the spring-loaded "lock button" which you can see on the outside of the tumbler.

3.Practice this on your new tumbler first so you get the idea: you need something small to get in that hole. Smaller than a coathanger: I used a mini flat screwdriver. When the screwdriver goes in the hole, the spring loaded "lock button" retracts.

4.Turn ignition to (position 2?) where the hole is accessible on the old tumbler, stick the screwdriver in (I had to bend the screwdriver slightly down to fully compress the "lock button."

5. Grab that black metal collar that encircles the old tumbler (the one with the key position indents in it). Turn it counter clockwise. The collar and the old tumbler with the key in it (and the screwdriver) should all screw slowly out until they're everything's free.

6. Make sure the new tumbler slides smoothly into the ignition assembly (i.e. where you just pulled the old one out) without putting the black collar on yet. A cheap tumbler might not have exact tolerances and may get caught up--make sure it slides in & out smoothly. If not, you'll need to get a new (proper MBZ) tumbler, or get handy with a file :eek:

7. Put the new tumbler inside the black metal collar, put the new key in the lock, turn it to the right position, put the screwdriver in to compress the "lock button"

8. Put that whole mess in there (into the empty and waiting ignition assembly). Screw the black collar down all the way. I found that the key wouldn't turn until I had seated the entire assembly in place, then backed the collar off a quarter of a turn, where it clicked in place.

9. Put the decorative silver ring back on, and congratulate yourself on saving yourself from the hassle, expense, and being stranded when that old tumbler decided to finally jam for good!

[Whirledge]

Many thanks! Ignition not stuck anymore, but I need instructions for tumbler removal and replace.
Now, to install the new tumbler with key that I ordered from the dealer and received after only a two day wait. A step by step procedure "Remove and Replace" would help me. I have two 2mm drill bits to use as pins, but my search for instructions here have been fruitless.

Thank you for helping me free my sticking ignition. My second 1986 16 Valve ignition was 'sticky' for several months, but after the car started I would forget to address the sticky switch. Shame on me for not taking care of the problem before the switch locked.

The symptoms before the ignition stuck: the key would turn a tiny bit, then stop well before the first position. After a little wiggle or two, the key would turn with slightly more resistance than a smoothly operating ignition switch.

The trick to get ignition to turn: I pressed an orbital sander pad against the back of the key in the ignition with the sander on and normal pressure on turning the key. Not an easy feat to hold the running sander and turn the key, but it worked! (What a great feeling, to have tried a suggestion from a member and have it work right away, after much frustration with a week of daily attempts to turn the key.) Unfortunately, the key sprang back to the off position when I pulled the sander away. OH NO! I said. I repeated the effort with the sander to have the key turn again and start the car. Whew!

Thanks. What a relief not to have to pay the high professional repair cost of a stuck switch,
Ted
1- 1993 300E 2.8 (28.3mpg on last road trip)
2- 1986 16 Valves (one converted to standard suspension)
1- 1970 VW Transporter Single Cab

[zak]

Just a thought....
Can the lock just be drilled out to accept any key, screw driver, nail clipper etc. to turn the ignition ?

This would eliminate the $350. cost.

[Robert Goodwin]

Maybe............................once you get past the stainless steel end cap that the key passes through. If you can get the tumbler out, you can drive it like you stole it, with a screwdriver.

Drilling the stainless steel cap is likely to result in a lot of damage to the surrounding area unless you have a way of keeping the drill bit from slipping off center.

Having replaced several of these, one as recently as last month, I don't really see how it could be drilled out. Right behind the cap is the first tumber and it is made of steel. The rest of them are brass.

As if all this is not enough, you still need to remove the steel lock cover or use drill bits up to about an inch in diameter. I am told that just drilling out the pin results in the use of several drill bits. I shudder to think about what this alternative will cost in dollars and time.

Don't know where the $350 price came from. Last I heard, removing and replacing a stuck lock and tumbler was over $1,200. Of course, this was probably at the dealer and included towing.