The ignition key on my '81 240D is some times very hard to turn, and then the next time operates normally. It did this a few times about 2 years ago, and hasn't since until just now. It usually turns freely, but sometimes very stiffly. No in between.

Tempted to spray some WD39 in there, but thought i would ask what the forum members think before doing that.

Thanks!

I would shoot some wd40 in there. I’m not sure why people always say don’t put it in there. It seems to evaporate off over time.

This will help you isolate whether the problem is in the lock cylinder or in the steering lock mechanism.

I wrote up my experience repairing my lock mechanism on my 300sd.

Jammed ignition lock - steering column mechanism worn

On this SD and on my old 240D the problem was the little wedge shaped release that the tip of the key hits to release the column bolt got worn. That being said, gummed or jammed lock cores happen too.

In your shoes I’d start by pulling the core. Get it out on the bench and give it a good spray down inside to get rid of old filings and grease. While it’s out you can get a good look at the column lock release down the hole and see if it needs work/replacement.

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79 300TD “Old Smokey” AKA “The Mistake” (SOLD)
82 240D stick shift 335k miles (SOLD)
82 300SD 300k miles
85 300D Turbodiesel 170k miles
97 C280 147k miles

The issue with wd40 is it attracts dust like a magnet, and leaves a gummy dusty residue that eats the leaves in the tumbler… a bad idea.

Contact cleaner and compressed air, with a light dose of graphite a few days later after it has completely dried out would be my choice…

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

How many miles on the car , the age will be evident in that mechanism over time . It will fail , best to address both and not risk the lockout of the tumbler . For time being I would start resourcing parts . Anytime I have this issue it’s not very much longer it locks up , a few months at the most .If you go for the tumbler , at least you can check to see if it’s like new or their a lot of slack in the movement .

X2 on the WD40. I stick the tube into the keyhole and give it shot. Besides lubing it flushes out metal fragments shaved off of your key.

Note people think that WD-40 will cause dirt to stick to it. Most of it evaporates. I mean I have been using WD-40 on my outdoor pad locks for over 40 years. Never once had them jam up due to dirt sticking inside of the pad locks.

Graphite is OK on door locks which have few steel parts inside of the tumbler and hence nothing to rust.

Anyway, that has been my experience.

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84 300D, 82 Volvo 244Gl Diesel

He is speaking of his ignition lock/key. How much dust do you suppose is inside of his car?
When the car is sitting there is no turbulence to shove dust inside of his lock tumbler. When you are driving the car, the Key blocks the entrance of dust into the tumbler.
There is theory and what works.

Long Beach is a dusty dirty place, and I would not hesitate to use and have used WD-40 sprayed into the exterior of the outside lock tumblers. Dust never seems to be an issue. And I live less than 1/4 mile from a freeway that serves the port of Long Beach, and it has heavy Big Rig Truck and car traffic on it stirring up dust.

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84 300D, 82 Volvo 244Gl Diesel

Personally, having had the inside of the steering Column lock/ignition switch assembly break in 2 places inside I would remove it and take it apart and inspect it. When I did that I also found that one of the discs on the ignition switch contacts was burned away and only the arm itself was making contact.

So, I made sure to get the whole assembly that came with a new Ignition Switch.

People have been mentioning for more than a year that the steering Column lock assembles did not seem to be available. Since it is going to fail someday it could be a good idea to get one now. If later, you don't need it you can sell it on eBay or here on the forum.

A year after changing the offending steering column lock assembly my lock tumbler innards fell apart.

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84 300D, 82 Volvo 244Gl Diesel

I sprayed some electronic contact cleaner in the key hole, and inserted and removed the key several times, and it came out with some greasy black stuff on it. Seems to be working fine, but it has only acted stiffly at random intervals, so time will tell. About 170K miles on the car. Not sure how to remove the mechanism, and hoping to avoid that job, as long as it keeps working smoothly.

Unfortunately, the issue is that to remove the steering column lock you need to have the Key turned to a specific position and the innards of the steering column lock need to be unbroken.
On my year and model (1984 300D), it is the same issue with pulling the ignition switch out of the bottom of the steering column lock. The key has to be in a specific position to do that.
If you can't turn your lock tumbler to the specific position, you cannot remove the outer sleeve that holds the lock tumbler in.

If you cannot turn the key to the special position steering column lock to the special position, there is a brass-colored pin that keeps the steering column lock from being pulled out of a bracket/mount that needs to be ground down or drilled out.

On my 84 300D I only need to turn the tumbler into the specific positon and use one pin through the hole in the tumbler later models may need it turned to the specific position and 2 pins.
For a W124
PeachPartsWiki: Ignition Lock Cylinder Replacement

What happened to me:
Steering Colum Lock (Ignition Lock Housing) causes Ignition Switch Failure

Another Type of Ignition Lock Tumbler Issue W123 Pictures

Other repair links:

Fast navigation Do It Yourself Links

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84 300D, 82 Volvo 244Gl Diesel

The tumbler is a 1 hour job. If it gets jammed you have a six hour job. Is the key a remake? I Recommend to obtain a new tumbler and or key, aftermarket(maybe NLA) or dealer. If you want the key to match it has to be the dealer. I waited to fix mine and was not happy when it jammed for good. If it is intermittent on the sticking you are likely headed towards a failure. I had to drill out the steering lock pin on a couple of W123's. One was just left that way. No steering lock. Also, most locksmiths recommend Tri Flow lubricant. It was first designed for bike chains. Trying a new MB key would be the easiest thing to start with.

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Chris
84 280sl
82 300d euro

Like so many others I learned the valve of not trying to half ass this assembly. Just get a new assembly and start fresh. Either that or risk being stranded or worse.

The contact cleaner seemed to help, but once in a while it will turn freely to start but act like turning it thru molasses in January in Alaska on turning it off. Thinking something gummy may have gotten in there that is only sometimes in the path of the mechanism.

The problem is like in my case it was a presumption that lock tumbler is the case when in fact for me it trends out to be the innards of the steering column lock broken in 2 places and an ignition switch that was on the edge of oblivion.

Why my opinion is when you have that type of issues remove the steering column lock and take a look. Look at how long those parts have been in service. Nothing lasts forever.

Will just have to wait and see what happens with the OP's car.

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84 300D, 82 Volvo 244Gl Diesel

There is a vacuum shutoff valve on the steering column lock. It is well known that when the vacuum shutoff diaphragm on the Fuel Injection pump becomes porous you get the crankcase pressure allows oil to be sucked past the diaphragm.

You can tell this by removing the vacuum line at the fuel injection pump and see if there is evidence of oil in the line.

If oil vapor gets into the vacuum valve on the steering column and it is cold, it would indeed thicken up inside of the vacuum valve making it more difficult to function.

Best of luck.

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84 300D, 82 Volvo 244Gl Diesel

A lot of good comments here .

RIGHT NOW, while you still can, take your registration to the M-B dealer or The Classic Center and order in a new ignition lock cylinder .

Put it in the trunk if you don't want to install it just yet, sooner or later you're going to need it and it comes with a brandy new key you can have copied, DO NOT use the M-B replacement keys ! they're cheap crap and the rubber head WILL break off in short order .

Just a thought : are you aware that sometimes, the steering wheel loads up against the locking pawl inside the column ~ the next time the key doesn't want to turn, see if moving the steering wheel a little bit in one or the other direction doesn't free it up .

WD40 kills lock cylinders, so says every lock manufacturer I've asked as well as had to replace more than a few after they were washed clean with WD40 then left to operate dry .

Graphite or the other stuff mentioned .

Dust isn't a problem, dry parts is, they wear rapidly .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better