About a month ago, the key on my 1984 300SD got stuck in the off
position. I did my homework and got it to turn THAT LAST time (after
about an hour of trying.) So I removed the tumbler and proceeded to
drive it by starting it with a screwdriver. Once home I
procrastinated getting a new tumbler since I was able to start/stop
the car with a screw driver. After a few days of this, I noticed the
ignition was getting stuck again. I eventually figured out that I had
to push a little latch inside in order to start the car. At that
time, I concluded that the tumbler did the pushing for me when it is
in place. So I hurried and got me a replacement (used) tumbler. (A
buddy of mine has an identical car that he uses for parts.)
I used it for about 2 weeks without any problems and I was getting
ready to order one from the dealer (since my buddy's was on loan) when
I noticed the key was sticking again. Well, last week, it got stuck
again. It took me about a week of trying (a few minutes here and
there) to get it to turn THAT LAST time again. So now I have removed
the tumbler again and am back to starting it with a screw driver.
Actually most times I start it with a pair of needle nose pliers so as
to not disturb the "latch" I referred to earlier.
At any rate, now I'm thinking the sticking is not due to a bad tumbler
(both tumblers turn fine when outside) I'm starting to think I have
some other issue going on. Perhaps the mechanism behind the tumbler
is what is faulty. I've done more homework but I have yet to learn
anything about this possibility.
Anybody here have any clues?
Anybody have detailed instructions on how to remove the cluster panel
to get to the mechanism that starts the car. If I can take it apart
maybe I can learn something.
Well, I don't have detailed instructions (yet), but I can tell you how
to remove the instrument cluster. You pull it out. Seriously, its just
held in by friction. To help me with this I made two "pullers" out of
wire coat hanger with a short (1/2") hook on the end, and a handle
fashioned about 3" away. (I read about the tool and technique here
http://articles.mbz.org/instrument/renew/ ). Slide one in each side at
about the 80C mark on the Temp gauge, and the 60 mark on the Tach (for
my cluster), then rotate the tool so that the hooks catch the sides of
the instrument cluster. Then pull, it comes out easier than you
Once you get it pulled out then you need to remove everything off of
the back. For mine, I found that the seat belt and glow plug lights
came out the easiest, then the clock 12V line (spade connector), then
the speedometer nut and line. Once you get those off you have a good
bit more room, and there are a couple electrical connections for the
tach and cruise (or something on top of the speedometer). The hardest
part is disconnecting the oil pressure line in that tight space. Its a
10mm (I think) open end and unscrew it from the brass housing on the
back of the cluster. One large connector (for dash lights, fuel, and
temp, and other warning lights) and you're done.
Once the instrument cluster is out of the way, then you will probably
have some insulation to move to be able to get down to the switch from
Disclaimer: I don't know if it would be easier to get to the switch
from the bottom by removing the lower kick panels or not, but for me
Unfortunately, thats the most help I can offer. I haven't had the bad
luck of my key not turning yet, but it may start soon. Quick question
though... Did you rekey the tumblers to match your existing key? Or
use your buddy's key for the tumbler you borrowed?
If the former, could it just be a really worn key?
Along those lines, who cuts keys for these things (other than a MB
Ok, more questions than answers, sorry about that, but maybe we can
I had an '89 260E whose got stuck in the ignition. Had to leave it
where it was parked for 2 days until I could find a shop that would
take a look. It was the tumbler, and it had to be ordered from TN
after I verified my ownership with the local MBZ dealer.
You are better off by chaniging out the entire ignition lock. I did that in
mine... I started out with a tumbler... then I find my ignition switch kinda
doesn't work... and realized the pin key broke off on the ignition lock and
then changed the whole damn thing.
Put a new tumbler in though...
Yes, I did it myself. It is not too hard. Instrument cluster out... lower
panel out... the trim plate around the ignition out... then turn to position
one... loosen the collar nut by the lock and steering column... use a stiff
wire like thick wire hanger and push that tab in... twist the assembly 90
degree and pull entire thing out.
To take of wire harness off the original ignition switch... key must be in
Mine had been getting progressively worse but always came up with that
one last turn. Until it didn't. At 9 AM. On the busiest narrow street in
Manhattan where we blocked one lane of three and soon attracted the
attentions of the Law. Called a tow truck and had the car deposited
with an MB garage on the Upper East Side. Cost some $400. But I no
longer worry about not being able to turn the key. Moral: if the
ignition starts to get flakey, don't wait. Fix it. Or better, have a
mechanic fix it.
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