|Phippsburgh said: (quoted from post at 09:40:32 09/14/10) In response to soundguy yesterday....is NAPA's AW 46 ok for NAA hyd.? What does iso stand for? The pail for AW 46 says there's 3 choices....32/46/68 meaning different viscosity grades light/medium/heavy.|
It is fine.
ISO is the International Standards Organaization and the AW stands for Anti Wear meaning it has a mild EP additive package as well as a rust and oxidation (R&O) package. The 48 is the ISO viscosity grade which is used for specifying the viscosity of hydraulic/industrial oils. The SAE grading scheme you are familair with is technically only intended for motor and gear oils. The ISO grading scheme is the actual viscosity of the oil measured in cSt at 40C. There are actually 18 grades ranging from 2 to 1500 where each step in grade corresponds to a 50% increase in measured viscosity over the next lower grade.
As has been discussed here in the past the hydraulic sump seals on vintage NAA tractors often leak into the transmission and differential cases. Since AW hydraulic oil is not well suited to those applications some folks opt to use a universal type hydraulic/gear oil product in all three sumps to guard against contamination. Universal Tractor Fluid (UTF) is simply a generic brand of the the M2C-134D product that became the recommended fluid from Ford in later years. You can use it in all three sumps.
TOH This post was edited by TheOldHokie at 07:39:50 09/14/10.