D6 9U oil

I Just bought a 1956 D6 9U cable blade electric start.
The mahchine runs like a top.
I was trying to find out what type of oil does it require in the clutch, final drive ect?
I know the engine gets Rotella like my truck.
Thanks

Oil clutch gets the same thing as the engine. If you wanted, you could use a drive train oil or tractor hydraulic fluid because there is no combustion gas contamination etc to deal with and the oil is used to cool and lubricate a clutch material which those fluids are designed for, but the original spec was for the same as the engine.

Final drives and transmission use a gear lube with the weight dependent on the temps you will be operating in. If very hot, 85-140, normal temps 80-90wt, if very cold, below 0*F, maybe a synthetic 50-70 wt gear lube would be nice or even 30 wt drive train oil if very cold temps.

Oils and lubricants have changed dramatically since the 9U was made and better fluids can be used than what was specified at that time. However, the large volume of each compartment can make it hard to go for the best quality available when I know the original fluid was nothing like as good as even a cheap modern day equivalent.

The clutch uses the same as in the engine.Back in the day Cat said gear oil in final and transmission,then in 70's said 30 wt in everything and I think they have gone back to gear oil.I use 85-140 gear oil in my 9u's.But I am in Cal were it never stays below freezing all day.The most important thing is make sure it is not dry,anything is better than nothing.
Over on Redpower they have gone on for days about 15-40 versus 30 wt engine oils in older engines and both camps have reasons for there side and claim years of experience with no ill affects.There is advise here saying us 40 wt in these older Cat engine,which may well be the best at this time but is something you will have to look for special .
Ray