77/8210's had common transmission and rear end hydraulic systems so it's one check point, one fill point for a common sump. Basically, Ford tractors work like this... if it's a 3 cylinder chassis tractor, the hydraulic and rear end/hydraulics are different sumps. If it's a 4 or 6 cylinder chassis tractor then they use a common sump. Again, I say CHASSIS. There are 4 cylinder tractors out there that are built on the 3 cylinder chassis such as the 4830 and 5030... and there are '4 cylinder chassis' tractors such as the 78/79/8210 that use the 6 cylinder engine.