84 126 300SD key/lock issues - PeachParts Mercedes-Benz Forum

kerry · #1 03-12-2011, 11:53 AM

Key is the high security key with different cuts on each side of the key. Issue occurs with both driver's door lock and ignition. Sometimes the key works fine. Other times it has to be jiggled and attempted to be turned multiple times before it works. What's going on? Had a replacement made at a locksmith with a machine that reads the key and produces a copy based on the original key and not on the existing key itself. New key has the same issues. Sometimes it's fine, sometimes it wont turn.

kerry · #2 03-13-2011, 03:39 PM

TTT

Nobody has any ideas?

curbill · #3 03-13-2011, 08:04 PM

Had the same problem with my 84 300sd 5 weeks ago. Went thru the process of ordering a new key and tumbler. Drove with the key in the ignition for 2 weeks until the parts came in. Had it installed and my wife went off to work on the following monday. 4 oclock that afternoon the steering wheel locked o her. Drove down and sure enough ellocko. Towed to mechanic and they ordered the whole locking assembly. Luckly they were able to unlock the wheel and install the assembly. So much for the tumbler purchase. Should have ordered the assembly to start.

tbomachines · #4 03-13-2011, 08:14 PM

Quote:

Originally Posted by kerry

Key is the high security key with different cuts on each side of the key. Issue occurs with both driver's door lock and ignition. Sometimes the key works fine. Other times it has to be jiggled and attempted to be turned multiple times before it works. What's going on? Had a replacement made at a locksmith with a machine that reads the key and produces a copy based on the original key and not on the existing key itself. New key has the same issues. Sometimes it's fine, sometimes it wont turn.

How does the locksmith determine that? The only ones who can get a direct copy of the original key is MBUSA and its some sort of algorithm off of the VIN (need proof of ownership). If the locksmith is just estimating the wear on the key it could be pretty well off...I would give MB a call and see how much it is to make an extra key that is 100% accurate to your locks. Also, if the tumblers are getting tired, you can squirt a little bit of graphite in there (do NOT use any other lubricant) to free up the tumblers. If the spare key from MB does not work well with the old tumbler its time to replace them. Trust me, you don't want it to be too late and have your key get stuck--its a huge pain to get out.

kerry · #5 03-13-2011, 08:25 PM

Not sure how the locksmith determines that but the machine was definitely not a regular key copier. It was a large computerized machine which required the input of the year make and model then the machine 'read the key'.
Why is it happening with both the door and the ignition?

vstech · #6 03-13-2011, 09:13 PM

likely, the locksmith made a bad copy.
or you could have two problems. many users spray wd40 or some spray lube, like silicone in the locks and grit etc gets in there. I'd get a healthy can of penetrating oil, and a can of brake spray. soak down the door lock with the penetrating oil, and let it soak for an hour. then use 1/2 can of brake spray on the lock, and notice the gunk that leaks out. blow in some canned air to dry the lock and see if it works right. graphite can be used after that.