Ignition Switch and Steering Lock Nightmare

[FalconOps]

Ignition Switch Stuck and Steering Lock Nightmare

I just want to share my experience that happened to me on my 1993 400E with over 193,000 miles:

A few weeks ago, the ignition key tumbler got stuck and would not turn. Thinking it was a worn key or tumbler, I ordered a new one but the new key didn't work and with the help of my friend, we both could not remove the ignition key tumbler even with the special tool (eBay and makeshift tools).

After spending a lot of money on towing, my friend ended up using a Dremel tool to cut out the metal cap and eventually got the tumbler out. He found that the clip, that holds the black cap, was broken which is why it wouldn't come out with the special tool. He also found that the steering lock assembly was bad as he couldn't unlock the steering wheel even with the tumbler removed. I had to buy diamond point rotary bits so that he can drill into the locking pin to remove the faulty steering lock assembly. So we ended up installing a new steering lock assembly, ignition switch, tumbler, and buzzer switch as well as having a new key.

The 400E was down for about a week and I roughly spent a little over $700 in parts, tools, towing the car, and buying resource videos from Mercedes Source. YouTube videos were not much help at all. I had no warning or issues with the key tumbler such as sticking and it just simply happened out of the blue.

My advice is that if you have never replaced the steering lock assembly on your W124, then I recommend to just do it so you won't get stuck.

 

[nocfn]

Years of heavy keys denegrate that tumbler and not sure which goes first. First thing I did when i bought was coco matts and a new key and tumbler.

 

[Harv]

Seriously guys. Clean and lube your tumblers.

It's a way bigger problem with W124s if something goes wrong than the old W116/123/126. It can turn into nightmares like we see above.

 

[gsxr]

Great post - thanks!

If you don't know the age of the tumbler... order a new one, VIN-coded, ASAP and replace it immediately (it will come with a new master key as a bonus). Cheapest $100 insurance you can have against this type of failure. Any time I buy a used 124, unless there's a record of the PO having recently replaced the tumbler, it's the first part I order. You can look at the date code stamped on the old tumbler after removal to see if it's original.

 

[r44raven]

Yep, many of us have been there/bought that tea shirt - and ended up some $s the poorer! As gsxr says, if you haven't yet replaced your tumbler/steering lock, do it now to avoid heartache further down the road!


!

 

[sprnova]

Great thread. Wanted to confirm the part number for this. 126-460-06-04 "Ignition Lock Cylinder"

 

[JC220]

Great post - thanks!

If you don't know the age of the tumbler... order a new one, VIN-coded, ASAP and replace it immediately (it will come with a new master key as a bonus). Cheapest $100 insurance you can have against this type of failure. Any time I buy a used 124, unless there's a record of the PO having recently replaced the tumbler, it's the first part I order. You can look at the date code stamped on the old tumbler after removal to see if it's original.

This reminds me - of all the jobs & parts I've replaced on my 500E the tumbler ain't one yet. I'll order a new one from MB this week!

In terms of lubrication as mentioned above, what is good for that? A little grease (Teflon, synthetic or Graphite?) applied to the new tumbler before installing?

 

[gerryvz]

MB makes a lock lubricant. It comes in a little spray can with a plastic tube to get inside the lock.

 

[FalconOps]

Great thread. Wanted to confirm the part number for this. 126-460-06-04 "Ignition Lock Cylinder"

The part number on my invoice says 126-460-02-04 and I had to give a copy of my vehicle registration to the parts adviser. They ignition lock cylinder will include one key. The list price was $90.00 plus tax.

 

[gsxr]

Great thread. Wanted to confirm the part number for this. 126-460-06-04 "Ignition Lock Cylinder"

NO! That is the generic lock cylinder... not VIN coded. The key included will not fit the doors or any other lock on the car. You don't want this one.

The part number on my invoice says 126-460-02-04 and I had to give a copy of my vehicle registration to the parts adviser. They ignition lock cylinder will include one key. The list price was $90.00 plus tax.

126-460-02-04 is the correct part number, and yes you will need to provide a copy of your registration (and possibly driver's license) to the dealer to prove ownership.

MB makes a lock lubricant. It comes in a little spray can with a plastic tube to get inside the lock.

Sadly, last I heard the official MB lube was NLA. If there's a new / current part number from MB I'd love to know what it is.
Update: The MB lock lube was unavailable for a long time, but is available again by summer 2020. New p/n is: 002-989-06-51-09

 

[emerydc8]

I've replaced tumblers in both cars, but my wife lost her keys yesterday so I am down one key on each car. My dealer is ruthless when it comes to gouging. They usually go 3.5 times MSRP -- because they can. Not looking forward to finding out tomorrow how bad they're going to screw me.

 

[gsxr]

I've replaced tumblers in both cars, but my wife lost her keys yesterday so I am down one key on each car. My dealer is ruthless when it comes to gouging. They usually go 3.5 times MSRP -- because they can. Not looking forward to finding out tomorrow how bad they're going to screw me.

I'd ping Jono, Naperville, Husker, and MBCC to see if any of them can help you out. 3.5x retail is sheer larceny.

 

[emerydc8]

Thanks, Dave. I'm in a push for time and have to leave for a trip before the end of the week, so I'll see what the stealer wants for the keys tomorrow. At least it's not one of those plastic remote keys that I see people carrying around. I will never own one of those.

 

[nocfn]

Just call Tom Hanson with the vin and he will send you the tumbler from Dallas with a key.

 

[JC220]

Sadly, last I heard the official MB lube was NLA. If there's a new / current part number from MB I'd love to know what it is.

I am headed to my MB dealer to pick up a new battery tray in 4 hours time (Damn you 500E Board! ) If someone has a PN for the MB lock lube spray I can check availability when I am in the dealer's

 

[speedy300dturbo]

The current PN for Mercedes-Benz lock lubricant spray is 002 989 06 51 but I believe it's been discontinued.

Volkswagen offers a similar looking (possibly identical?) spray, part number G052778A2.

 

[Alex89]

Oh great info. Did not know this can be such an issue. When I bought the car I got 3 or 4 keys so not sure if mine was changed. Will have to check the date on mine too.

Is it possible to check with the dealership it anybody ever ordered the replacement since they do ask for VIN and everything?

 

[JC220]

The current PN for Mercedes-Benz lock lubricant spray is 002 989 06 51 but I believe it's been discontinued.

Volkswagen offers a similar looking (possibly identical?) spray, part number G052778A2.

Thankyou for the info. There is no stock of these cans currently according to paragon- BUT it is orderable with an unknown delivery date. Price £11+VAT

So I placed an order for a can & I guess it'll turn up sometime! I am not sure if it will pull chicks like a tub of Gleitpaste..... but it seems like a good idea for when I am installing a new tumbler.

 

[gsxr]

At least it's not one of those plastic remote keys that I see people carrying around. I will never own one of those.

Ugh. I just had to order two of those... even worse, I *might* need to pay their service department even more $$$ to marry the key(s) to the car. Still trying to figure out if I can do this myself via SDS; or if the dealer will not release the keys to me without going through the service department. I'll find out within a week or so.

The current PN for Mercedes-Benz lock lubricant spray is 002 989 06 51 but I believe it's been discontinued.

That is my understanding as well, the MB lube went NLA sometime in the last year or three.

Volkswagen offers a similar looking (possibly identical?) spray, part number G052778A2.

Awesome find! Based on the bottle cap pictured, and the same size (50mL)... I wonder if this might be re-branded Liqui Moly 1528?
EDIT: Some vendors (ECS Tuning) show the VW lube as NLA, but other vendors still have it available as of October 2025 (click here).


I pinged FCP (a Liqui Moly dealer) to ask if they could obtain the #1528 juice or not. I'll let y'all know what they say.

UPDATE: FCP said they could not get #1528. But they did not say why: NLA? Not allowed for USA import? They don't want to bother because they don't think anyone would buy it? Regardless, FCP is out as a potential source.

 

[nocfn]

just some basic reminders, like the engine and trans fluid levels, more product is not a blessing. Do not think you are benefitting your locks by too much product. Enough to lubricate, that's it...

 

[gsxr]

just some basic reminders, like the engine and trans fluid levels, more product is not a blessing. Do not think you are benefitting your locks by too much product. Enough to lubricate, that's it...

Yep. It's a once-every-few-years thing. Squirt a bit in, then insert/remove the key a few dozen times, wiping the key off in between. A single can is usually a lifetime supply for a dozen-car fleet.

 

[Allgonquin]

Well, as a result of this thread I ordered and received a new lock cylinder to install preemptively. $122.21 including sales tax in MD and 10% MB club discount. Waiting on the tool to install it. Decided not to try to make my own. New key fits perfectly in old cylinder. Ordered on Tuesday, received on Thursday. Came from Dallas (Grapevine).

 

[Harv]

Guys, spraying something into the tumbler while it is inside the steering lock and dash is like putting deodorant on when you really need a shower.

You need to pull the tumbler from the car and clean it properly. These tumblers collect a ton of dirt and grime from the keys everytime you use them. Pull the tumbler and dunk it in some kind of hard cleaner. Soon that clear solution will be totally dark with all the crap that will fall out of it. Then after it is dry, lube it with a synthetic grease from the back and the front. Then the tumbler should feel butter smooth when turning the key.

 

[sprnova]

Just tried ordering a new ignition switch from mboemparts.com (Naperville) and got rejected. They emailed me with the following:

"We have removed part 126-460-02-04 your order for the following reason: the part you ordered is classified as a "Theft-Relevent Parts" through Mercedes-Benz. This part can not be sold on line, and can only be ordered through your local authorized Mercedes-Benz Dealer"

In my order I offered to send a scan of my registration if they needed it, noting that there was no way to attached it to the order.Anyone else get rejected when ordering this part online?

 

[RicardoD]

MB Classic Center took my order.

I have confirmed that we can order the lock tumbler 126 460 02 04 from the Mercedes Classic Center in California. I just emailed and asked. I then provided a scan of my driver's license and the title on my car via email. I get a 15% discount from the $105 list price as a MBCA member. I started with an order for my 560SEC and will follow up with an order for my E500.

I also got the same rejection email from mboemparts.com as I tried there first.