92 500sl cylinder lock replacement

[lymlyt]

Hi-
Im running on borrowed time. Only one key, the key fob, turns the ignition lock. All the other (4 keys), non fob keys don't. So I suspect a bad tumbler whichfor some reason one key doesn't agitate. Thus, the need to replace the ignition key cylinder. My car is 1992 500sl 130K miles. Questions:

1. How difficult is it to replace?

2. Should I replace anything else at the same time?

thanks!!

[Gilly]

About a 5 on difficulty with some special tools required, and I'd definitely replace the ignition switch, I would wonder why there is one key that does work and the rest don't though.

[lymlyt]

Gilly, thanks as always for your input/expertise.

Update:
1. Repalcing the tumbler(cylinder lock) resolved my problem-all keys
now work.

2. I was informed by Mercedes that just the tumbler(cylinder lock)
could be replaced. Incorrect! The service prats dept said it was an independemt replacement and the shop foreman agreed and said it could be done in less than an hour. Wrong. (it would have required many "new" parts and much more labor-read on)

3. Assuming Mercedes had an exact tumbler(cylinder lock) replacement
for a 92 SL (which they don't) it would also require a new and exact ignition lock cap replacement (which they don't), it would be a about an hour labor and $100 in parts. So, local Mercedes service was way off!

4. According to Mercedes, to replace the tumbler(cylinder lock), which is slightly different than the original as is the ignition lock cap, requires the purchase of about 5 other parts to make it all fit correctly. Costs for the parts over $600 and about 5-7 hours labor.

5. I ordered a tumbler(cylinder lock) from Mercedes, provided exact year,model, and VIN and received a new tumbler(cylinder lock) and one new key. Tested all my other original keys, and all worked. My indy ordered a new ignition lock cap but because of slight yet significant differences
of the tumbler(cylinder lock) and ignition lock cap, they couldn't be replaced like for like or fit for fit. Very long story short, my indy modified slightly the new tumbler(cylinder lock) and reused the orginal ignition lock cap (using epoxy to secure the tumbler) and all is good. My indy, as usual was nice to me, total cost $100 parts, $225 labor. Knowing what we now know,
to do it again, about: $75 parts, $125 labor.

Also, had to remove IC (replaced all bulbs during the "event")
and drivers knee panel to affect repair.

hope this helps others.


thanks

-andy