IH 254 front axle (4wd)

[Steve254]

IH254 with 1160 hours.
I am looking to change the front axle oil.
Manual calls for 85W-140, but doesn't say how much.
Does anyone know how much is needed to fill?
My best guess is maybe 1.5 gallons. Just a visual guess......
I just want to make one trip to parts store.

Thanks.