In 1999, Chevrolet replaced the C and K-series of pickups with the Silverado. The 2002 Silverado came in three different sizes 1500, 2500 and 3500HD. The engine sizes ranged from a 4.3-liter V-6 that produced 200 horsepower in the 1500 to an 8.1-liter V-8 that produced 340 horsepower in the 3500HD. All three sizes of the 2002 Silverado had five rear axles to choose from, 8-3/5 inch, 9-1/2 inch, 9-3/4 inch, 10-1/2 inch and 11-1/2 inch. All of the axles undergo the same process to replace the differential fluid, only the fluid capacities change.
Place the wheel chocks around the front wheels of the Silverado to prevent them from rolling while jacking up the truck.
Raise the rear of the truck using a floor jack and slide the jack stands beneath the axle. Lower the jack until the Silverado's weight is supported only by the jack stands. Remove the floor jack.
Slide the drain pan under the drain plug on the rear differential "pumpkin" -- the large orb in the center of the rear axle.
Remove the check and fill plug at the top of the "pumpkin" with a ratchet. Remove the drain plug at the bottom of the "pumpkin" with a ratchet. Allow all of the gear oil to drain from the rear differential.
Clean the drain plug, and then the check and fill plug with a clean shop cloth.
Reinstall the drain plug and tighten it to 20 foot-pounds on the 9-3/4-inch rear differential and 24 foot-pounds on all other size differentials, using a torque wrench.
Fill the differential with 75W-90 synthetic gear oil through the check and fill hole. The 8-3/5-inch differential requires 2.41 quarts., the 9-1/2- and 10-1/2-inch differentials require 2.75 quarts., the 9-3/4-inch differential uses 3 quarts. and the 11-1/2 inch uses 3.83 quarts.
Insert the check and fill plug and tighten it to 15 foot-pounds on the 9-3/4-inch differential and 24 foot-pounds on all other sizes, using a torque wrench.
Raise the Silverado up from the jack stands with a floor jack and slide the stands from under the truck. Lower the Chevrolet to the ground. Remove the wheel chocks from the front wheels.
