Park the Polaris Ranger on a level surface and run the engine for 2 to 3 minutes. Turn the engine off, clean the area around the drain plug at the bottom of the oil tank, place a pan to catch the oil underneath the drain and then open the drain to release the oil inside. Replace the drain plug and tighten. Remove the crankcase drain to release residual oil.
Replace the crankcase drain. Remove the dipstick and pour the new oil into the oil tank. The recommend oil to use is Polaris Premium Synthetic OW-40, or PN 2871281. It takes 2 quarts of oil.
Changing the oil filter at the same time that the oil is changed is a good idea. After draining the oil, remove the oil hose and screen fitting from the bottom of the tank. Clean the fitting and reinstall. Remove the oil filter and replace.
After changing the oil filter, the engine will need to be primed before it can run. Set the gear in neutral and apply the parking brake. Clamp off the vent line 2 inches from the oil tank. Run the engine for 15 to 20 seconds. Remove the clamp from the line.