2009 Chevrolet Silverado 2500 HD Extended Cab Owner's Manual - Page 459

To disconnect the jumper cables from both vehicles do the following: 1. Disconnect the black negative (−) cable from the vehicle that had the bad battery. 2. Disconnect the black negative (−) cable from the vehicle with the good battery. 3. Disconnect the red positive (+) cable from the vehicle with the good battery. 4. Disconnect the red positive (+) cable from the other vehicle. 5. Return the positive (+) terminal cover, to its original position. Also, if a vehicle has just been driven before checking the fluid level, it may appear lower than normal because fluid has traveled out along the axle tubes and has not drained back to the sump area. Therefore, a reading taken five minutes after the vehicle has been driven will appear to have a lower fluid level than a vehicle that has been stationary for an hour or two. Remember that the rear axle assembly must be supported to get a true reading. How to Check Lubricant Rear Axle When to Check Lubricant It is not necessary to regularly check rear axle fluid unless you suspect there is a leak or you hear an unusual noise. A fluid loss could indicate a problem. Have it inspected and repaired. All axle assemblies are filled by volume of fluid during production. They are not filled to reach a certain level. When checking the fluid level on any axle, variations in the readings can be caused by factory fill differences between the minimum and the maximum fluid volume. 2500HD with 6.0L and 6.2L 5-49