as much as i usually stick with makers specs on stuff,running hd engine and trans oils,i have changed to john deere hygard trans oil in my primary after a bit of clutch drag when cold and harsh 1st selection. we run hygard in all out tractors,in trans and hydralics [ commomn reservoir ] ,hydralics,planatery final drives and front axles, so i thought i would give it a go.smoother [ not perfect ,but improved ] cold 1st selection,and less drag. i had stripped and checked the clutch components and and found all good.prior to this there was bit of compensator noise on start up [ there is a little play in the unit ] but this has quietened down since changing the oil over.so far so good. if the oil works on wet clutchs' and final drives it will be fine.my trans changes fine with formula 1.engine oil consumption is almost zero with no topping up between changes [ every 4000 km ] with the HD engine oil and 65.000 km on the clock.