Door key problem

[jbach36]

Over the last few days, when I put the key in the door and try to turn it, sometimes it won't turn. I've put a bit of additional pressure on it, and it's as though it's metal hitting metal, just a dead stop, won't turn. If I turn the key left, then right, it'll work. I've been working on a home in a questionable area, so I don't know if someone stuck something in there, or if the key is just messed up.

It seems the key in the ignition works fine, at least so far. I don't see any burrs or metal shards on the key. Is there anything I can do for the lock itself, like using door lock graphite or a bit of lithium on the key to help lube and loosen the lock innards a bit?

jeff 1991 300d, 128k

[blindwolf]

It sounds more like a lock linkage problem that a cylinder one. The linkage should be cleaned and lubed, at the least. Removed and checked for excess wear and play and replaced if necessary,if the first step does not correct the problem

[81300sd]

First step would be some graphite powder for locks. WD-40 works well too. Being a water displacing oil, it will remove any moisture that ices and freezes your locks.

[Gene Horr]

WD-40 is not for moving parts unless you want them to stop moving in the future. The volatiles will offgas in a couple of months and leave a tar-like gummy sludge over everything. Great for something you want to waterproof but the worst thing you can do for moving parts.

[leathermang]

I like PB-Blaster for this sort of thing....

[rcounts]

Originally Posted by leathermang

I like PB-Blaster for this sort of thing....

Ditto,

My locks froze overnight - couldn't even get the key into the locks.

I thawed them quickly by taking a spare key (all metal with no plastic head) clamping a set if vice-grips on the head, heating it over a gas flame, and working it into the lock, then letting it sit for a couple of minutes.

Once they were thawed out I sprayed a good sqirt of PB Blaster in there to displace the water so they don't freeze again...

[bgkast]

If it's not just frozen you may need to follow this: http://www.peachparts.com/Wikka/W123DoorLock

[nickofoxford]

MINE DO THE SAME D@#^ THING.

It's not that the locks are stuck, just really stiff. Shooting it with PB only worked until it rained, now it feels like something rubber has swelled up in mine so it's stiff. And sometimes I have to turn it to the lock position, then turn it to unlock. It's like you have to release something in there to actually be able to unlock. Im gonna pop my door panel off later and see what I can find.

[81300sd]

Originally Posted by Gene Horr

WD-40 is not for moving parts unless you want them to stop moving in the future. The volatiles will offgas in a couple of months and leave a tar-like gummy sludge over everything. Great for something you want to waterproof but the worst thing you can do for moving parts.

The only sludge I have seen with it is from dirt and grime sticking to it. I use it for waterproofing engine blocks in storage and they do get grimy. I have used WD on locks plenty of times without the locks getting gummy, but I also use graphite oil in them. I only use WD when they freeze.

[81300sd]

Originally Posted by nickofoxford

MINE DO THE SAME D@#^ THING.

It's not that the locks are stuck, just really stiff. Shooting it with PB only worked until it rained, now it feels like something rubber has swelled up in mine so it's stiff. And sometimes I have to turn it to the lock position, then turn it to unlock. It's like you have to release something in there to actually be able to unlock. Im gonna pop my door panel off later and see what I can find.

Shoot the lock/latch assembly with a good solvent then follow up with your preferred spray type oil, while you are in there do the same to the window regulator and door check mechanism, although they should probably have grease instead of an oil. You will thank yourself later as it makes everything so much smoother.

[showme]

I've recently removed and cleaned 2 different lock tumblers of trunk locksets for my wife's 81 300D, and I can tell you that there was enough crud in both of them to make me wonder how they worked at all before. I even shot PB blaster in the first one for days, and it didn't work still. Granted, some of what was in there is the original grease, but you have to figure dirt, fine key shavings\dust, and the general junk of the world are going to get in there. The last ones' brass tumblers needed the black grime cleaned off of them. Once those tiny springs get gummed up, they aren't going to work right, either. THere's a DIY link in the resources section up top. But before you attempt that, my suggestion is have white paper spread out on the table\bench and a small cup or plate to keep your parts in. Especially that little BB on the back end. That puppy will run away in th wink of an eye. I'd try your linkage first, like mentioned above. Do the tumbler cleaning as a last resort. It's not hard, but it does require patience and nimble fingers. Good luck.

[nickofoxford]

Originally Posted by 81300sd

Shoot the lock/latch assembly with a good solvent then follow up with your preferred spray type oil, while you are in there do the same to the window regulator and door check mechanism, although they should probably have grease instead of an oil. You will thank yourself later as it makes everything so much smoother.

Yeah i've found out these window regulators are quite fun . I redid both the fronts over the summer, that was a blast! I'll definitley shoot some grease around in there though.

Im thinking this is more of a tumbler mechanism problem, as I recall the linkages were all fine as of last month, and it has done the lock-unlock back and fourth deal on and off since I bought the car.

Looks like it's time for some remote locking engineering

[Squiggle Dog]

I had this happen to me for the first time this morning. I took a heat gun and put it next to the slot where the key goes in to allow the heat to enter the lock cylinder, while holding the end of the key in the path of the heat gun to heat up the key. Then I stick in the key and usually it works itself free. After this I squirt in some lock deicer/lubricant and work the key around a bit. It worked for me!

[tyl604]

Jbach - I have had an '81 300SD since 1983. For several years my driver's side lock worked the same way as yours. To lock it with the key I would have to turn the key in the opposite (unlock) direction and then turn it the correct direction to make it lock. Something would click when I turned it toward unlock, you could hear and feel it, and then I could lock it by turning the key the other way. I never figured out why it worked this way; however, there is something inside the door that has pushed and bent outward the door panel and it is exactly where the locking mechanism resides. So I have always thought that something in the locking mechanism was binding and pushing the door panel out and bending the door panel.

Cannot remember when this stopped. I think it stopped after all the door locks stopped working and I had to replace the actuator in the driver's door. In any event the key works properly now - yes, it is the original key that came with the car in 1981 - and I still have pushed out areas in the door panel.

I realize this does not help you with a fix but I am glad at least that someone has experienced the same problem. Is there anything inside your door pushing out?

[jbach36]

I sprayed a bit of WD 40 on my key (never spray into the key lock as you might over-do it), and it has helped out. So far, so good.

Thank God I don't need to rip anything else apart, like the door, or tumbler.

Thanks,

jeff