date of manufacture re camshaft repair 1977 300D

Posted earlier question about camshaft replacement on 1977
300D, Steve Brotherton and Ed Richardson replied. The car was delivered on 8-16-77 in Houston at the dock. The other date on the metal owner ID card, stamped at the dead center at the bottom of the tag, is 6-15-77. Engine ID and chassis ID numbers as follows:

123130-12-051082 chassis
617912-12-023259 engine

How do I tell the actual date of manufacture from these numbers? If MB supposedly "corrected" the failing camshaft problem around March 1977 by hardening the surface and doing whatever else they did in re-design, this may suggest
my camshaft does not need to be replaced.

I agree a visual inspection is really needed. The MB tech who works on the car nights & weekends has done work on it
for 8 years and has done valve adjustments on it previously.
His feeling that the camshaft needs replacement is either based on his past visuals and knowledge of the car or merely
relying on shop talk about older diesels needing camshaft replacements at 120,000 miles.

I am not sure which is right, but knowing the date of manufacture will at least help me in discussing the situation with him. He's not trying to gouge me, but he could be relying on the shop talk ... I'll have to ask him about the visual, although I do believe I now recall him telling me after the last time he adjusted the valves that the camshaft was looking worn (this may have been at about
the 90,000 mile checkup, done just after Dad died in 1992 and I brought the car up from Texas). Car has 121,000 miles on it now ...

Thanks for the help !

Bruce Sanford

[stevebfl]

We are talking about an issue so old that it may not be verifiable the easy way. That would be to look in the parts film or CD. I just tried this yesterday for someone asking about the 107 subframes and whether they still had factory help for failures. It didn't work.

What I would expect is the note that one original part was replaced (as of some specific engine number in this case)with an updated version. In the case of the SL all traces have been removed of the original number (I was trying to find out if the 380SL had the original subframe or was it only 450SLs). Being at home I can't check for you.

The way to visually check is to look at the rocker arms. The final fix had a very hard surface welded to the rest of the rocker arm. The original arms were all one piece and had the cam load surface machined out of the original material and then surface hardened. This was not enough and they had to change the material for the Cam pad. If you look under the cam pad it is easy to tell whether the thing is one piece or "glued" together.

It really doesn't matter what you have if its wore out. You will be getting updated stuff if you replace with new parts. (unless you use the wrong aftermarket stuff). If your tech says its worn then I would take his advise.