UPDATE II: I came across a website that offers a 4 hour DVD on rebuilding the Mercedes OM617 Turbo diesel engine for $79.98. It is a little pricey, and it is not technically for the W115, but it may be a valuable resource reference for someone to have.the engines are similar enough that I am sure that the DVD will contain much info that is relevant to the W115.
Check out the short example video.
Here is the main website:
UPDATE: I am taking Peachpart forum member Army's suggestion to include some other online resources, such as mailing lists and forums that can be a resource for W115 owners. Thanks, Army!
Peachparts Diesel Discussion Forum:
New Mercedes forum catering to the W114/115 Series:
Kaleb Striplin's Mercedes email List:
Any other suggestions are welcome.
This is a partial listing of some of the service manuals that are available for the Mercedes W115 300D. I have copies of all of the manuals listed below. There may be other manuals available. In addition, Mercedes did offer the official Factory Service Manual, I believe. I do not know whether it is still available through Mercedes, but you can probably find one on EBay or Craig's List from time to time. I believe that the FSM is available on CD, and that is what I bought on eBay a few years ago. Or at least I THINK it is the FSM that I bought.
There is no Haynes Manual for the W115 that I am aware of. The Haynes W123 Manual has info on the early W123 300D engines, which are similar to the W115 300D engines. There are some differences, however, so proceed carefully.
Anyway, here is the partial list of Mercedes Service Manuals that may be helpful to the W115 owners out there:
Mercedes-Benz Tune-Up Maintenance
Gas and Diesel 1958-1976. Clymer Publications. 1976.
Chilton's Repair and Tune-Up Guide Mercedes-Benz 1974-84
Chilton Book Company. 1984. Part No. 6809
Haynes Automotive Repair Manual
Mercedes-Benz Diesel 123 Series 1976 thru 1985
4 & 5 cyl. Haynes 63012. Haynes North America, Inc. 1986.
Chilton Mercedes Coupes/Sedans/Wagons
1974-84 Repair Manual 48300. Chilton Automotive Books. Published by Haynes North America, Inc. 1997. Includes Wiring and Vacuum Diagrams. Or so it says. I don't see any wiring or vacuum diagrams here for the W115 300D. Those are very hard to come by, in my experience. If anyone has info on that, please email me and I will be happy to post it here.
I have a pic posted of the cover of this manual, if anyone is interested. It is in the post on May 10, 2011 entitled "Getting "The Backseat Driver's Baur and Grill Club' Prepped for Marlene's Restoration".
I will try to get some pics of the covers of the other manuals I have listed here, so you can see what they look like.
Mercedes-Benz Model 114/115 Service Manual Library
Complete Service Manual. I purchased on EBay from a Vendor in Turkey a few years ago.
MERCEDES BENZ W114 W115 SERVICE REPAIR MANUAL 114 115
5/14/2011 Update: Thanks to forum member Diesel911 in PeachParts Mercedes diesel discussion forum for posting this link as a source of DVD and CD Manuals.
Here is a link to the thread in PeachParts Diesel Discussion, another valuable resource, btw:
Thank you, Diesel911!
This link was posted by PeachParts forum member Army. Although it is for the W116, there may be some useful cross-references for W115 owners.
Thank you, Army!
I always like this sort of info on all the W114/115 Series: