Is there an Alldata or other 3rd party shop manual for the W140?
 

Has anyone tried it?

Thanks,
Sixto
91 300SE
87 300SDL
83 300SD

I just recently got a 1 year subscription for my sl600. I felt it was well worth the $25.00 for the late model 129's (mines a 97). Covered ADS and a few other things I was looking to nail down.
not sure about the 140's though.

for what thats worth.....

CR

97 SL600
93 750il
77 630csi
70 R/T SE Charger
68 Corvette Roadster

Yes
 

Yep, Alldata has the W140 ... at least they cover my '96 S500. Have had a subscription with them since December.
As you've found, there simply doesn't seem to be any manuals anywhere for these cars... which makes the Alldata on line manual a good buy just for that fact.
Overall, the system works pretty well; its obvious that most of the pages are right out of Mercedes literature.
The bad news is that much of it isn't intuitive... you have to hunt a bit at times to find things... and the formats don't make it any easier. For instance, the electrical schematics are broken up into multiple pages making it all but impossible to follow a wire from one end to another without some real effort.
Some mechanical procedures are missing all together.
The good news is that you can download the drawings and pictures to your computer if you wish. Most procedures are there and many of the illustrated diagrams are excellent.
Good luck.
KenP