Yep, on engine air compressor so same oil as in the engine. Cummings wouldn't give me a model or part number and nothing stamped on the housing. It was just giving an oil change before I bought last year and only put maybe 3500 miles on it. I'm thinking since dealer did the oil change it would be standard oil, they won't tell me since I gave them a bad review. If standard, what would it be?
Sam Spade, it gets its oil from the engine. Cummings wouldn't know, they'd tell me to bring it in so they charge $270, just to look and tell, "I don't know".