The ignition lock housing in my '83 300CD was replaced/repaired(!?!) by the PO and is currently held in place by a hose clamp.

I can turn the switch and start my car with a flat-bladed screwdriver - or I can remove the key and leave the engine running.

So, in addition to a new ignition lock housing, what do I need and how do I make them match up to my currently matching and functioning door and trunk locks?

The ignition parts list at Fastlane include the housing, the cylinder, the switch and the cover w/ some trim accessories.

Do I order a new lock housing for under the dash, then order a new lock cylinder from the dealer with the VIN to have the keys match? Can the dealer VIN records go back that far? (I can't use the online M-B system epc.startekinfo, but have to go manually due to the age of the car). I presume since all the other keys work correctly, including the glove box, that they are original.

Can I get a new ignition cylinder re-cut to match an existing key, or do I have to go the other way and get the doors and trunk re-cut to match the new ignition cylinder?

I'm not a fan of multiple keys on the key chain, so I don't like the idea of separate door and ignition keys. I've also read the advice on getting a junkyard replacement housing, but due to the problems caused if/when they fail (key stuck in ignition/won't turn - correct? And that wouldn't solve my screwdriver problem) I'm inclined to go with a new replacement housing for the $150 or so estimated cost and fix the cylinder with an actual key.

Any recent experience with keys of this vintage from the dealer? Or from locksmiths on cutting new door or ignition keys or cylinders?

When I replaced mine a year or two ago, my shop bought a replacement from the dealer to match my keys. As I recall, it took a few days and cost under $100 for the cylinder and a new key.

Vin coded key and lock assembly prices have risen in the past 3 months,
They are now closer to 200 dollars for the set but still worth replacing since they also include a brand new key.

New safety and anti theft laws have made the whole process stricter.
Try and stay away from any aftermarket ones as they are really bad quality and wont match your key set.

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W123 1985 300TD naturally aspirated

my key wont even turn to the # 1 position, how can I replace the ignition??

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1976 300D W114
1979 300SD W116

it involves removing the dashboard and disconnecting the igntition tumbler from the steering column.

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check this link. should help you to find other posts if you need to. the idea is to vibrate the key with a palm sander or other such device while you turn it. Then you must remove the lock cylinder ring and replace the ignition assembly or you'll end up doing this again.

Cure for stuck Ignition Lock

I've never done it, but it makes sense. I've sat in my car trying for a half hour until it finally unstuck. Had to leave the key in the lock for a few days while I waited for the new part to arrive. Luckily, I work on a Navy base, and there wasn't much chance of it being stolen.

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mjk

'84 300SD 119KMi (Liesl der Diesel)
'84 300D 326KMi when the oil left (former parts car)
'82 300SD 253KMi (new parts car)

Do you have a pic of what parts are broke/missing in yours? Not sure what you mean by ignition housing. The ignition tumbler is held in with a round steel threaded collar to the steering column IIRC. The ignition tumbler cannot be taken apart for re-keying as far as I can tell but the door and trunk tumblers can (from what I have read) so your best bet is to get a new ignition tumbler with key and then re-key the door and trunk tumblers.

Mercedes tumbles in the W123's have brass waffers. similar to this



Note the gunk? That's from spraying lubricant into the tumbler and the lube attracting and holding onto debris (wafer and key shavings,dust). Brass is self lubricating and need no lube so do not spray anything in there. Any shavings from the key or wafer should fall out of the tumbler as the tumbler is rotated from use, unless there is lube in there. As more gunk build up, that tumbler in the pic will jam in due time. I have cleaned out 2 stuck/ gunked up Mercedes tumblers by washing in hot soapy water, leaving it totally dry and it's been working fine since.

Attached Thumbnails

 

No need to remove the dash...and the entire lock housing and ignition switch need to come out, not just the tumbler. I would imagine it is the same for w114 and w116 chassis though it wasn't specifiied.

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TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth

i'm pretty sure the tubler sticks out a centimeter or so from the opening in the dashboard. you can pull that part of the dash outward, but you might bend it permanently if you do. your choice I guess

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Once you remove the retaining ring (if possible, given specific situation) it makes it much easier to wiggle it out. Also, once you loosen the steering lock mechanism you can wiggle and finagle it out. Admittedly it takes a lot of patience but IMO it is much easier than removing the entire dash. When I had tumbler issues, I got the entire ignition/lock/steering lock mechanism out under the dash only removing the ducting and the above-pedal kick panel. It wasn't easy but thats one of those jobs that just isn't no matter how you stack it up.

Here's my story/method, sounds like this guy may have to follow suit if his tumbler is stuck:
(Urgent!) Am I out of options? W126 Ignition tumbler

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TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth

My problem was solved a while back. benzerhead116 now has a slightly different problem from the original. Check here for more info on ignition switches. Be advised the threads are now crossing multiple models, so specific techniques may vary. In the first link there's a reference to a locksmith template that lets them drill the collar on the 'single hole versions' and you can remove it easily. That's in addition to the other techniques, using sanders, voodoo dolls, etc.

advice on removing ignition tumblers

There's also a good how-to here: W124 Lock Cylinder Replacement: How-to

The above link has pics of some of the parts that broke on mine. The other part that's held in by the hose clamp is the actual ignition switch housing under the dash.

http://img.eautopartscatalog.com/live/W01331605516VAL.JPG

That's still in mine, still with the hose clamp. I'll get around to it someday.