What's the 2002 Chevy 2500hd rear differential fluid capacity?

The 2002 Chevy 2500 HD has a rear differential fluid capacity of just under four quarts. To drain the fluid, locate the drain plug on the bottom of the differential, it accepts a 3/8 inch square drive. Place a drain pan below the drain hole and remove the filler plug on the back of the differential using a 15mm socket and then the drain plug. The 75W-90 gear oil is pretty thick and will take us several minutes for it to fully drain. Once the fluid has slowed to a drip, replace the drain plug. Adding the fluid can be a little tricky, it's best to use a hand pump that attaches to the 1 quart bottles. Add enough fluid so that it's level to the bottom of the fill hole.