I have a Troy-Bilt Horse Rototiller that calls for GL-4 . . . NOT GL-5 This is due to the bronze shear gear and supposedly the additives used in GL-5 gear lube are hostile to these Bronze parts. This is hearsay but I've heard that Synthetic Gear lube with a GL-5 rating is NOT harmful. Such as Mobil1 and Royal purple?
Now to confuse matter worse I called Troy-Bilt and they now call for GL-1 85w-90? Now if GL-1 85w-90 is ok why not GL-4 85w-90? What's the difference?
So what is the difference between GL-4 & GL-1? Is Synthetic GL-5 bronze gear friendly?
I use the Troy-Bilt Commercially and it sees very heavy use and the gear oil needs to be changed ASAP
Thanks
Now to confuse matter worse I called Troy-Bilt and they now call for GL-1 85w-90? Now if GL-1 85w-90 is ok why not GL-4 85w-90? What's the difference?
So what is the difference between GL-4 & GL-1? Is Synthetic GL-5 bronze gear friendly?
I use the Troy-Bilt Commercially and it sees very heavy use and the gear oil needs to be changed ASAP
Thanks