Recent discussions with friends who are also members of this forum prompts me to present a caution that probably should be repeated every few years for emphasis. EMD diesel engines do not use the same kinds of engine lubricating oils that are commonly used in smaller automotive diesel engines. The lube oils for EMD diesel engines are limited to less than 10 ppm (parts per million) of zinc. This limit is recommended in order to avoid the mistake of using incorrect lube oils designed around the requirements of high speed engines that use additive packages which are corrosive to the bearings in some EMD diesels. You can check with your oil supplier to confirm that the lube oil they have available is suitable for your EMD engine. It is also a good idea to send in a lube oil sample from time to time to confirm that you have received and are using the right type of oil. The need to use the correct oil also applies to use of oil in assembling components for the engine, like the buildup of cylinder power assemblies. The applicable standards for EMD lubricating oils are defined in Maintenance Instruction 1760 which can be obtained from your EMD distributor.

PC

OOOOOOOPPPS

I have seen the same 15W-40 Delo oil used in both without problems. Also how does the significant reduction in Zinc in automobile oil in 2004 affect this? For the record the reduction of zinc has lead to issues for some people in rebuilding engines of vintage cars.

Robby

The zinc is the traceable indicator of an additive package that was commonly used as an anti-scuffing supplement in oils for automotive size engines running aluminum pistons. As noted above, the additive can be corrosive to the bearings in many EMD diesel engines. The degree of damage varies with concentration of the additive in the oil and consequently is difficult to predict. There are a few EMD engines around (a relatively small and recent part of the total population) that use bearings that are not affected by the high zinc oil, but I doubt that many of them have found their way to museums, most EMD's with that construction are still in service on the railroads.

I once saw a major railroad backshop fail 16 cylinders in a freshly overhauled GP35 on load box testing because the guy who built up the power assemblies ran out of the correct EMD engine oil and "borrowed" a can of oil containing lots of the high zinc additive from his friend who ran the fork lift truck.

PC

The same goes for many Fairbanks Morse engines. We use Caprinus (zinc-free) oil in our FM H12-44. Naturally, we also use it in our RS-3M (EMD 567B engine).