Replacing ignition tumbler

[bgiovan]

Greetings!

Just picked up my 2nd Benz - a 1980 W116 300SD.  The ignition key was sticking and rather than contend with a nasty repair, I got a new tumbler and am in the process of installing it.  I did read the section in the service manual and it seems pretty straight forward.  I have the detent released but cannot for the life of me get the cylinder cover to unscrew.  Anyone ever run up against this? 

Thanks in advance,

Ben near Detroit, MI (USA)

[koan]

The chrome trim ring needs removing before the cover will unscrew all the way out.

I found the detent a bit tricky to depress sufficiently to let the cylinder rotate.

There are a two or three different cylinder locking methods, have a look at the online manual.

Maybe diesel is different.

loan

[Papalangi]

I have the type 2 on my '76 so I can't directly help but it looks like you have to keep the detent pressed the whole time you are unscrewing the cover, or at least most of the way until the back of the cylinder is pulled past the point the detent drops into.

Michael

[Martin 280s]

I hope this helps, I posted this on another forum some time ago.

Tools

1 - medium Philips screwdriver
1 - 13 mm combo spanner or socket and ratchet
1 - 10 mm C spanner
1 - 22 mm socket and short extension and ratchet
1 - medium sized blade screwdriver
1 - small punch and hammer
1 - 5 cm2 mirror
And a lot of patience!

First, remove the steering wheel and instrument cluster, 22 mm socket for the steering wheel nut and 10 mm C spanner for the oil pressure gauge. Carefully disconnect all the wires and pull of the multi-pin plug in a straight line. Then remove the knee bolster from below the dash, there are around seven Philips screw all told. Once all the covers from under the dash have been removed loosen the C clamp at the base of the steering column (10 mm C spanner) and remove the two 13 mm bolts from the top of the column, now the column should be loose enough to shake a bit. You really do need this small about of movement!

Using the mirror find the clamp on the steering lock/ignition barrel, remove the 10 mm bolt. Remove the chrome ring from around the ignition switch, careful not to break off the tabs. Now you're ready for the fun part. Put the key in the ignition and turn it to 2, using the mirror find the locking pin on the steering lock and push it down. THIS CANNOT BE DONE WITHOUT TURNING THE KEY!..it took me 3 hours to discover this part, I'd only done this on a W108 before and they don't have a locking pin! Now you should be able to waggle the ignition assembly, pull it far enough out of the column to hold the locking pin down inside the steering lock barrel. Remove the key and twist the assembly round so the multi-pin terminal faces upwards, you'll need to get it past the dash so do this carefully, you won't want to make things worse. Having done this, continue to pull the assembly out.

Once the ignition assembly is out, remove the three screws which hold the multi-pin terminal in place. Having discovered the crimping had lost its grip, I used a small punch and light hammer to recrimp the edges. I also lightly coated the moving parts of the ignition/steering lock with Vaseline before assembly

Assembly is much easier so I took advantage to clean and check the general state of things under the dash. Before you try to put the assembly back in, push in the lock at the end and this will hold the locking pin down. Do not make any jerky or sharp movements or this will cause the pin to pop out and you'll have to start again. The rest is just a reversal of everything else.

[koan]

Excellent description Martin but bgiovan only wants to remove the lock cylinder not the complete lock assembly.

Have a look at job 46-640 in the library.

koan

[bgiovan]

Indeed!  I almost needed to remove the whole enchilada though so thanks Martin!  I did get the tumbler out (finally!) and tomorrow morning (Sunday am here in the states) will go ahead and try to put it back in.  It's winter here in Detroit and I was in need of a warm house and a cold Guiness so I called it a day!

It was on pretty tight but finally busted it loose.  I ended up taking a flat blade screwdriver and a small hammer and using the indentation in the stop check grooves as a place to wedge the screwdriver in and tapped it up until I got it to loosen.  The face cover took some scrapes thought so I repainted it.  After that extraction, I spent most of the day ripping out the interior.  I have some questions on seat restoration but will search the archives first then post if I'm still stuck.  Shredded wheat everywhere and the previous owner at some point rolled house fiberglass insulation and packed each spring in the rear seat cushion.   

I cut my teeth restoring a 1980 240D (W123) 4spd/Crank Windows last summer.  This 1980 300SD W116 has a lot in common but a lot different with Klima I and higher quality parts.

Best to everyone for their tips.  I'll report back on this ignition tumbler issue.

Ben near Detroit

   

[Papalangi]

mercedessource.com has a little book about seats.  Covers most of the 70's cars and what fits what.

It also covers the pool noodle method of seat spring supplementation.

Michael

[kanda]

Okay what happens when the key wont turn and the steering wheel is locked.
How to remove the ignition tumbler. Urgently required because car is stucked for 3 day already

[koan]

Okay what happens when the key wont turn and the steering wheel is locked.
How to remove the ignition tumbler. Urgently required because car is stucked for 3 day already

That happened to me because I didn't heed the warning signs - the occasional difficulty turning the key.

I just kept wiggling the key and wheel and eventually it released, it took many, many and many attempts. Jiggling the key in and out a little, pushing the key to the sides and turning back and forth. Maybe some WD40 or similar down the key slot and around the barrel would help.

If it can't be unlocked the common wisdom is to drill out the lock barrel.

koan

[TJ 450]

My 450 has done this once, with an old, worn key. I have since acquired a replacement key and it works perfectly with the old barrel. I probably should have replaced the lot as a set, but it works.

Tim

[kanda]

Finally i got it repaired.
I had to drill out the pin and changed to used one which got from the backyard people.
And i was trying to figure out what when wrong on jammed unit,oh my got it is not easy to take it apart. I am still trying to. managed to grind out the black casing and checking in or cause of failure.