When removing and reinstalling a full-floating drive axle shaft on a school bus, the technician should:

1. Skip cleaning the mating surfaces to save time
2. Reuse the old gasket regardless of its condition
3. Apply engine oil to the axle gear teeth instead of axle lube
4. Clean the flange, use a new gasket or sealant as specified, and torque the axle flange bolts to specification