I have used SAE 90 wt from Tractor Supply in my 53 3100 in trans and rear axle. Currentl I have the GL5 in both trans and rear axle.My trans shifts much smoother with the GL5. The 3 speed takes a 1.5 pints and 4.5 pints for the rear axle. Follow HRL advise on how to fill.

Wilbur 53