Truck Repair: shifting problems on GMC 1973 truck, seal leaks, automatic transmissions

Question
What should I look for if my truck shifts late and downshifts early?

Answer
Hello Dustin,
I don't work in automatic transmissions, but it sounds like the governor seals are leaking, and the governor isn't getting full pressure, or the pressure is just low.
Is the fluid level full, and clean?
Also, if the suction filter seal leaks, it could be getting air in the system.

Van