Transfer cases are used by four-wheel-drive vehicles, such as the Silverado 2500HD, to distribute engine power to all four of the wheels. It accomplishes this with a series of gears housed inside of it. These gears need proper lubrication to keep them from grinding against each other. Like any lubricant, transfer case fluid will wear down over time and need to be replaced. By performing this replacement every 30,000 miles, you will keep your transfer case working properly for many years.
Remove the four bolts on the skid plate underneath the transfer case. This will provide you much easier access to the transfer case's drain plug and fill plug.
Place an oil pan underneath the drain plug and remove the drain plug using a socket wrench. The drain plug will be on the side of the transfer case near the bottom.
Bolt the drain plug back into the transfer case once all of the fluid has drained. Use a torque wrench and consult the owner's manual of your Silverado 2500HD to torque the drain plug to the proper pound feet of torque.
Remove the fill plug using a socket wrench.
Screw the fill nozzle onto the top of the automatic transmission fluid bottle.
Pour the fluid into the transfer case until it begins to flow out.
Bolt on the fill plug using a torque wrench. Consult the owner's manual of your Silverado 2500HD for the proper torque amount.
