Timberjack 230E Eaton Axle Question

[Mountain_d]

My 1978 230E has Eaton axles. I never had the hubs apart but someone mentioned to me that the fluid in the hubs mixes with the fluid in the differential. Is that true? Last year I put a different fluid in my hubs (not EP - extreme pressure rated - so supposed to be easier on the brass) but I ran regular 80/90 in the diffs. If those fluids do mix then I guess I was wasting my time. Maybe the turning axle moves fluid from the diff to the hubs? Any comment from anyone who has had these apart would help. Thanks.
Mountain D

[Firewoodjoe]

I know mine would run back and forth. Weather it had a seal at the axle shaft or not a can't remember. But even if you put new seals in it who's to say in time the seal fails and your swapping oil again. I just ran yellow metal safe oil in the hole machine to be safe. And easy. 

[bushmechanic]

This is correct, the oil free flows from both planetaries into the differential and vice versa. I assume you have the brass pin planetaries and not the steel ones with the needle bearings. There is a space between the axle and the housing and that is how the oil moves back and forth. When your tipped to one side the oil will run downhill to the lower planetary, then go back when leveled or tipped the other side down.   

[Mountain_d]

Thanks for the info Bushmechanic. It would seem to me the level of the fluid in the diff is lower than the hub and thus the hub level would not be maintained, but I guess that is not the case. Yes, mine has the brass pins. 
Firewood Joe, what fluid do you run? I guess the GL number is what to look for to protect the yellow metal? If anyone else can suggest a good oil for this? I didn't mind spending money on an expensive oil for the hubs as they do not take much oil, but those diffs hold a lot of stuff so it can get expensive.  I appreciate the form for questions like this. Thanks again. 
Mountain D 

[Firewoodjoe]

 I used syn power valv. 

[Ed_K]

 Isn't regular 80-90 gear oil ok for brass? I use 80-90 in my gearmatic, it has a brass gear in it.

[Firewoodjoe]

No

[ehp]

fluid runs across the whole axle ,

[Mountain_d]

Thanks, Firewood Joe. I will look at options from your list. 
Most other loggers in my area seem to use regular 80/90 and dont seem too concerned about the yellow metal. Maybe that is how they were trained from those who worked years ago and the replacement brass components were readable available.