w123 key tumbler not the issue??
 

Hi,
My key was sticking and unable to turn at all. After a lot of wiggling, I managed to get it to turn and took the tumbler out. I read that once you experience this, you should replace the tumbler however with the tumbler out I'm able to turn it easily. Upon further investigation, it looks like the little ramp/steering lock could be the culprit. In the locked position, it requires some effort to slide it over. I have to push it over a light bit as I turn the ignition. Anyone discover this as well?

I don't want to pull out the whole locking mechanism, but has anyone figured out a way for the tab to not slide over and engage the steering lock? I don't mind if I lose the steering lock feature. Maybe jam a piece of paper in there? I'm not convinced that grinding down the locking pin will do anything as that little ramp thing appears to be getting stuck??

thoughts?

Thanks

Take a look at the two links below, I'm hoping that they'll be helpful to you to address the tumbler/key issue.

Mercedes-Benz W123 Ignition Tumbler Removal | W123 (1977-1985) | Pelican Parts DIY Maintenance Article

Mercedes-Benz W123 Ignition Switch and Assembly Replacement | W123 (1977-1985) | Pelican Parts DIY Maintenance Article

Several Years ago I had the innards of the steering colum break and it acted like it was the Tumbler that was the issue.
About a month ago the lock tumbler fell apart.

There has been 2 other members that had other parts inside of the steering colum lock break.

In my 1984 300D, it wasn't the tumbler but rather a "spring detent post" in the innards which was the problem. You must remove the steel cover plate on the key stalk to access it. The stalk must be out of the car for this, which is a bit tricky since you must pull the dash hole forward a bit to swing it clear, plus push a hard-to-see release button to pull it out. You can only push that release in when the key is in a certain position.

This spring post is thin die-cast zinc or such. It breaks off, then jams the rotating mechanism. It seems so wimpy that I am surprised it hasn't broken off in more cars. Mine no longer has that spring detent, so the key doesn't click into positions as solidly, but hasn't ever rotated while driving. Of course, don't hang heavy junk off your key or you will have problems, in many cars especially recent Chevy's.

I should have removed the steering lock rod while I had the stalk out and that cover off, since I doubt the anti-theft is worth the risk of jamming the steering wheel. I debated that, but left it in to be "correct". I staked & epoxied the steel cover plate back. Good luck.

Thanks guys.
Bill - This sounds very similar. So if I pull the stalk out and remove the plate, should I be able to remove the spring detent thing as well as the steering lock rod? From my inspections, I'm pretty sure my issue is that detent spring thing. When I attempt to turn the inside with needle nose pliers after it has locked, it is a bear to turn unless I assist/push the spring thing to assist in moving it a bit.

If you can't easily turn the switch with the tumbler out, then the tumbler certainly isn't what is jamming it. Of course, insure your steering lock isn't tight against the switch (all cars). You have to file or pry out the stakes in the die-cast aluminum (?) body so you can remove the steel plate. If you spring detent has broken, it will just shake out.

You can then remove the steering lock rock if you desire. Those probably don't help much in anti-theft since it took just a few weeks for criminals to learn how to defeat them. Plus, no loser would steal an old M-B diesel unless they believe the prices asked on craigslist.

I had the same issue, thought it was the tumbler so I took it out and just started the car with a screwdriver. The next day the lock mechanism wouldn't turn at all. I had to reach up under the dash with a hacksaw and cut it out so I could start the car and get home... Don't let that happen to you.
Bought a good used assembly from a member, put my old tumbler in it and completely forgot about the problem.

lol

Thanks!

Buy a new steering lock with switch. End of story. Your rigged up setup is only going to work for so long before you are drilling out the entire unit.

Same experience. The tumbler was fine in my 240d. It was something in the mechanism of the steering lock that was binding. I got a nearly new assembly off a guy on eBay for something like $100. I looked into trying to clean up the innards with a file but I gave up for some reason...I think it was hard to open up.

Several years ago I replaced the tumbler when my key got so I had to jiggle it to turn it.

But I also used JB Weld to glue that locking pin permanently back in the housing so that if the mechanism ever fails again I will still be able to get it out without major surgery.

Richard

Like this; Steering Colum Locking Pin epoxied in.

It also makes the Key easier to turn so there is less stress on the components.

When the Steering Colum Lock is out inspect the Ignition switch. In the pic the circled area shows one side of the points is entirely gone.

When you buy an new steering Colum Lock you get a new Ignition Switch and New Vacuum Shutoff Switch along with the colum lock.

The other pic shows the part number for the steering colum lock. I bought it from mercedes but it was made in france.

http://www.peachparts.com/shopforum/diesel-discussion/333785-steering-colum-lock-ignition-lock-housing-causes-ignition-switch-failure.html

Thanks guys. I put in an order on a new locking stalk thing. As much as I want to alter the existing one, my hope is my other electrical gremlins might go away.

Oh yeah. Thx, the photos jogged my memory. Things were binding up and this little pin wasn't moving. Wow, I should have filled it in like you. That would have saved a few bucks.

In order to depress the pin the steering coulum lock needs to be in that position that you were in when you removed the Lock Tumbler. If it is not in that position you cannot depress the pin. (I am speaking of the pin that I epoxied down.)

It depends on what broke.
In my case it was the piece that went down into the Ignition Switch that broke. The actual locking mechanism that locked the steering colum was OK.

My opinion is that if you pull out your Lock Tumbler because it is not turning correctly you might as well pull the Steering Colum Lock out and inspect the Ignition Switch and the innards of the Steering Colum Lock to see of they are OK or right on the edge.

Right. I recall mine was functional but it was hanging up internally due to wear. I imagined a big groove had just worn in the metal inside and was hanging up things.

I didn't realize I could freeze it in the unlocked position.

Or..how do i remove the plate. If i can remove the innards..i might just return the assrmbly. Thanks

There is plastic Safety Belt Switch attached to the Steering Colum Lock. You are going to need 2 old stye Bobby Pins, the ones that are black or brown and made of thin flat metal. If it has those plastic numbs on the end they need to come off.
You need to slide the bobby pins into each side of the switch between the Aluminu Housing in order to depress the plastic hooks that are built into the Switch.
Also the Steering coulm lock plunger has to be maipulated to push up on the switch so it can be pulled out of the hole.
In the 2nd pic the yellow arrow shows the direction that the switch has to be pushed to get it out and the red arrows show where the bobby pins go.

Well this is a pic of my damaged Steering Colum Lock that I sawed apart lengthwise.

The Steel Plate #2 is well crimped into a recess n the Housing. However, when the plate is off you can only get the large spring out.

Part #1 has the shaft broken off one end but that needs to come out I believe the same direction as you took the Lock Tumbler Out. When that is out #4 and #5 and that small spring inbetween them can come out throug that hole the plate was removed From.

I can't remember what needs to be done with the locking pin and spring in order to get the #5 out. In fact since I cut the Colum Lock apart I don't think I don't think I took it apart in the normal manner.

Wow! This.is.Awesome! Thanks for the pictures and explanations. I gave up on removing the rear plate. Maybe ill try and rip out that small spring through the saftey seatbelt harness Either way, this great. Thanks.

The steel plate is pretty well crimped in. It would take some grinding of the aluminum to get it out.
For someone else remving that plate it could be epoxied back in place with JB Weld the one that takes 2-4 hours to cure. I say that because I don't think the fast curing epoxy is as strong as the slow cured one.

You got that right. The regular JB Weld is the strongest epoxy I have used, (and I used a lot of epoxies in my boatyard), while the Kwik version is pretty poor.

Richard

The photos in post 19 don't look familiar from what I remember in fixing my 1984 300D's key switch assembly. I don't recall a seat-belt interlock switch, but perhaps there was. If so, it wasn't anywhere near the shiny steel plate. I don't see the plate in the photos. It sits furthest from the steering wheel. I had to pry it off to get at the innards where I found the broken detent spring-holder post. As I recall, that plate was staked in 4 places by slightly crimping the die-cast aluminum over it. I either beat them back w/ a flat screwdriver or filed them off (forget), but it didn't take long. It was secured fairly tight when I knocked it back on, but I used epoxy as assurance.