How cold do you run in? Unless very cold, I would run gear lube in the final drives. At one time, CAT was recommending 30wt in everything, but I don't think that lasted too long.
The rollers take 30wt drive train oil. I think that is a non detergent oil as opposed to a motor oil. There is a special nozzle to put on an oil pump to fill the rollers with.
My 941b manual calls for 30wt diesel engine oil for the rollers, idlers and final drive