What type and weight of oil do you use in a international 500c bulldozer not the engine oil the gear oil?

For an International 500C bulldozer, the recommended gear oil is typically a multi-viscosity gear oil, such as SAE 80W-90 or SAE 85W-140, depending on operating temperatures and conditions. The specific weight and type can vary based on the manufacturer's recommendations and the specific application, so it's always best to consult the operator's manual for the most accurate guidance.