fluid cap. in rears n trans

[Cowboy_Customs]

What is the fluid capacity in the rear of an 82 freightshaker class8 OTR tractor?? (sorry, i dont know what the axles are) N whats the cap. for an eaton 15speed?
Also, does anyone know what fluids (viscosity) are supposed to be in both? Im looking into buyin a sweet classic of a truck.
Bronze metallic 1982 freightliner classic flat top 60 inch removable sleeper with, what looks to be a 300 inch stretch, 15 speed, n a cummins NTC-400.
Super nice, other n the fact its sat for a few years, its got what were Brand new when it was parked, brakes, and 24.5 LP michelins all the way around. Damn nice for the money. Im going for a test drive finally, next weekend, I got to get pics. Now that I got a Digital for christmas I can do that!!

 

[PackRat]

The tranny should be between 3 and 3.5 gallons. The recommended lube for Eaton/Fuller transmissions is Synthetic 50w.

The rears are probably Eaton or Rockwells. All ours are 6.5 gallons between the two. I never can remember if it's 3 in the front or 3 in the rear. We run Synthetic 75w90 in all ours.