Tree Farmer C7E Query

[Koopsy]

Hello, I've recently purchased a 1980s Tree Farmer C7E and I wanted to change out all the fluids and filters. Would anyone know what kind of engine/tranny oil this machine would take? I'm up in Northern Ontario where the winter drops around -30'C in January and the summer peaks around +30'C in July.
The machine has a Cummins engine, Clark Winch, and a Clark 3 speed powershift.

Any information about this machine would be appreciated.
Bobby

 

[Simon C]

Engine would be good in cold weather with Petro Can Duron 0W40 or Shell T6 0W40. The transmission can run on 30 Weight. have seen them with 10 weight or even 10W30 Diesel engine oil. Thinner is always better in cold or tranny pump might not want to pick up. Have seen some Clark torques and trannys also on Dexron III before. Winch could be any ones guess. Maybe operators manual will give some clues if you are luck enough to find one.
Came from Northern Ontario originally.
Simon C

 

[Simon C]

75W90 Differential oil in axles and planetaries most likely.
Simon C

 

[old-iron-habit]

Our C6 Tree Farmer back in the late 70s in northern Minnesota had ATF in the Clark tranny from new. We never worked below -25 degrees though, to much other stuff seemed to go wrong when it got really cold.