Engine: Recommend Fluids 1940 Commander

[Mmcghee1024]

Hello everyone, what would some of you guys recommend for oil and trans for a 1940 commander

has straight flathead 6 and a t86 with r7 overdrive

Thanks!!!

[StudeRich]

Same as all Studebakers with Manual and Overdrive Trans.

With Overdrive, fill it first when level, then the Main Case with Mineral Oil SAE 90 or 85-90 Gear Oil must be GL-1 WITHOUT EP (Extreme Pressure Additives) available at NAPA and Farm equipment Stores (Tractor Supply).

GL-5 is used in the Differential Only.

[Mmcghee1024]

What about engine oil? Thanks

[Corvanti]

when i purchased the '40 Champion - 170 c.i. engine with no oil filter, the P.O. (a SDC Forum member) stated to use 30 weight non detergent oil. (the '40 was a 23,000 mile "Original Survivor"). non-det oil is available at your FLAPS. he also said to change the oil every 1,000 miles or spring/fall if not driven that many miles.

but if the engine has been rebuilt with all the sludge removed, a detergent oil should be fine. i'm using Shell Rotella 10W/30 in the '51 currently with the 170 and no oil filter. it and some other oils like Valvoline Racing Oil has ZDDP in the mix. many threads can be found yay or nay about using ZDDP and if it is needed for flat tappet equipped engines. i'm on the "yay" side - it certainly doesn't hurt the engine.