Fixed my lock cylinder on driver s side
 

Hi folks:
I just thought I would share this with you.

My car's driver-side lock stopped responding to key after behaving wierd for 6 months or so. During those 6 months tried everything including, WD-40, silicone spray, liquid wrench, lithium grease, brake cleaner, graphite lock spray etc etc.. you name it.

Also got a 15 bucks new key from dealer. Nothing worked. Not even an improvement. The key would go in but not twist. All other mechanism of locking were good. So I was sure that it was the lock cylinder.

Took the lock-assembly out and decided to take it apart to get to the cylinder. A very easy job. There is a small pin ( looks like one in the watch strap) that needs to be removed by using a small nail an tiny hammer. Once thats out, the cylinder can be removed easily by putting the key in the keyhole and pushing the cylinder out from other side.

I saw one of the square tooth on the cylinder was not fully retracted when the key was in and that was the tooth that would have prevented the twist of the cylinder, so pulled it out with a small plier and there was a small brass spring under it which was bent and out of shape. Pulled the spring out, slide it over a eye glass repair screw driver and manipulated till it was straight.( you can find such springs at locksmiths place too). Replaced the spring in its place, put back the metal tooth, cleaned the whole lock cylinder with engine degreaser, then brake cleaner.
Refitted the whole thing in reverse sequence and BINGO it works like a new one. Also lubricated with graphite lock spray.

Total cost $0.00
Total time 40 minutes
Job satisfaction......... PRICELESS.
:) ;)

In summary-- if your lock is not working and its for sure the cylinder mechanism, its worth fixing it yourself or a locksmith.
I am sure a locksmith would charge you about 20 bucks for such a job( afetr you have removed the lock assembly from the door). Its still better than getting a new lock with a different key for 90 bucks. or an old one from junk yard for 40-50 bucks and again with different key.

Hope this helps some folks.


MVK

MVK:

I think the best phrase in your write-up was "job satisfaction.....PRICELESS". I continue to be amazed at the MB's ability to get fixed and run well verses the popular culture's idea of throw away cars. Congrats

Don

Thanks Don.
I thought no one will see this big write up.

MVK

MVK
Good show. I will file your repair away as it may happen to me some day. Thanks:cool:

MVK great idea I saw it,and I'll file it for future use;) Doesn't it feel great when you tackle a problem like that and it turn's out for the best.Bear

Yes it sure makes me feel good. Also the fact that its a very little thing that most of the times is fixable with little or no money thus avoiding major expense.
Like fixing the alternator carbon brushes, blower motor carbon brushes, replacing bearing and brushes on Auxillary cooling fan, fixing the aux water pump etc etc. to name a few.

I thinks these cars are very good and home-mechanic friendly.

Thank you all for your support.

MVK

MVK,
Thank you for the post. You gave me the confidence to go after my non-functioning trunk lock. turned out to be merely a stuck slide in the cylinder (grease and other gook). CLeaned it, put it back in, and Viola! no more need to let the vac. lock the trunk!
Thanks again!!

You are welcome Wallknight.
Thats all we need once in a while- A little xtra push to get courageous enough to tackle a job that otherwise looks impossible.


MVK

I'm curious: If the key would not turn, how was the lock removed from the door handle?

I've got a spare handle (without a key) that I want to get MY keyed cylinder into, because of the alarm switch. I've got the handle all apart (found all the roll pins), but can't get the old cylinder out since I don't have a key. Any ideas?

MVK, I have the same problem. Your write-up is excellent. Can you (or someone) tell me how to get the lock assembly out of the door ? I do know how to get the door panel off. I 'll probably go ahead and do the check strap this time, if I have to get in there. Driver's doors take a beating. Thanks all.

I'll be trying this on my new 240 Tomorrow!

My drivers door lock works worse and worse as the temp falls
I have put graphite and wd-40 in it a plenty, the wd-40 helps quite a bit, but it wears off. In a year or two I'll probably just have to get a new lock for it. The passenger one works so flawlessly, I wish the drivers one felt/worked like that....can they be switched? :D :D I would imagine not because of the vac locks switch thing....but maybe they can.....anyone know?

I would try taking it apart and taking a look. It doesnt sound like it is too dificult of a procedure. My key wont even turn the lock. :(

Non-turning locks as usually related to failing/worn leaves or springs that are basically done.

OR the tumbler is wearing out and the leaves now wobble around in there and don't work properly (my problem).

Just remember that the spring was messed up for a reason...I would not be too terribly suprised if you are back in there before too long with a very similar problem. Next time you are at the wrecking yard start lookin for a passenger side door lock tumbler to put your leaves into. :)

Thats what I did on the SD...I've had that door lock out about 7 times. *sigh*

Ya get good at it after awhile ;)

Yes they can the two handles are identical and will quite happily work on either side,I know as I've done it in the past.Just be careful when taking the handle off when it moves but feels like its catching on something it is,just jiggle it off don't be tempted to give it one sharp pull:eek:

This is what I did on my drivers door on my 91 300D. Same problem. Key would not turn. I sprayed brake cleaner in the lock cyl then blew it out with an air hose. Repeated several times. Also would spray the brake cleaner then insert the key several times then blow it out. Did this until the key started working. Then used lock grafite (sp) lube. Total job time was about 2 or 3 min. Was done about 1 year ago and still working.

hmm my lock is doing the same thing.. i guess ill take it out and rebuild it like the author of this post did

That's the real beauty of these cars.... You can repair them at a minimal cost.

It's also the great value of this forum... You can find out how to repair them by people who have done the job and are willing to share the information.

Interesting article here on re-keying similar locks that explains the "leaves" and springs well.

http://www.pelicanparts.com/techarticles/mult_lock_rekey/mult_lock_rekey.htm

Pictures would really help other members.
 

Pictures would really help other members.

If anyone has a chance to add pictures, please remember to note which year, make, model, door/trunk/glove box, for each lock/picture.

It is fun to tinker with them.

I have added this thread to:
ShopForum > Technical Information and Support > Diesel Discussion
Organized MB DIY links post: Steering:
http://www.peachparts.com/shopforum/general-information/135055-organized-mb-diy-links.html

When I get around to fixing mine I'll post pictures. I didn't get to it today. I got distracted by some a$$ rear ending me in my other car then speeding off. :mad:

I'm trying this process this morning. And I will be startring within m inutes. If I get anywhere, I'll be snapping pics.

yes yes take pics so i dont screw up.. id like to be able to lock my car at school

Did you pop a few caps in their hoopty? :D

MVK wrote:

"The key would go in but not twist. All other mechanism of locking were good. So I was sure that it was the lock cylinder".


I hope you will not consider my question as being stupid, but when you wrote that key would not twist in the lock - did you mean that it would not twist to any position - either the right (locking position), or the left (unlocking position)?

The reason for my question is that since last week my driver's side door lock ( '84 300Sd T/D) key will not twist to the right (locking position), but does twist to the left (unlocking position). WD40 and machine oil have not helped at all. So I am wondering if I have a similar problem to what you had.

OK. I didn't really get too far. I ended up just trading for the passenger side (my drivers side was siezed). For those who inquire about locks that are completely siezed, plan on breaking the rod that connects the rod to the lock mechanism inside the door. I couldn't get it out without doing so. JB Weld? As for removing the actual cylinder, I didn't really see a means to seperate it from the housing with out some special tools. It actuaslly looks like it's riveted in. Good luck!

You are most likely going to find a worn out leaf holder (tumbler I beleive?) and the leaf no longer moves properly.

Mine did this too...before it got REALLY bad and just stopped working all together.

Thanks for the reply, Brandon - my thoughts also.

I've got mine all apart and cleaned up. You wouldn't believe all of the goo that was in there. All of the leaves move freely now. When I took it apart most were totally frozen. I have been documenting the procedure and will post it when I am finished.

I completed the how to for this procedure but have no place to host it. PM me if you have space for it. Thanks. -Bryan

Look at this for your answer
 

Look at this for your answer.

mercedesshop DIY wickie page!!!
http://www.peachparts.com/shopforum/general-information/139117-peachparts-diy-wickie-page.html

Thanks for the input Bgkast, what you did will be on my Spring list of to-do's as soon as you document the proceedure.

Here's the DIY
 

Thanks bgkast for your door lock DIY.
Here it is:
http://www.peachparts.com/Wikka/W123DoorLock

This is a great write-up, I thought I would just make one comment. The great thing about these cars is that there are so many cheap and easy things we can do to fix small problems such as this. The lock cylinder repair is one of those CLEAN, enjoyable and satisfying repairs. Except for the part when you get all done and find out that you still have to go to a locksmith because the soft, brass leaves are too worn and don't engage completely when the key is inserted. For those of us who enjoy immediate gratification and spending no money, never fear. I had a few leaves that stuck out 1-2mm, so with the key inserted, I very lightly used a small bench grinder to grind the long leaves flush with the cylinder again. This worked like a charm for me, the key slides in and out and turns very easily. However my spare key (which looks to be much more worn than the main key) will not work in it, so if your key is in bad shape too you might be out of luck.

A new key from the dealer will fix the worn key problem.