2006 Chevrolet Tahoe Owner's Manual - Page 415

All-Wheel Drive If your vehicle has the LTZ package, lubricant checks in this section also apply to this vehicle. To get an accurate reading, the vehicle should be on a level surface. If the level is below the bottom of the filler plug hole, you'll need to add some lubricant. Add enough lubricant to raise the level to the bottom of the filler plug hole. Use care not to overtighten the plug. Transfer Case When to Check Lubricant Refer to the Maintenance Schedule to determine how often to check the lubricant. See Scheduled Maintenance on page 6-4. What to Use Refer to the Maintenance Schedule to determine what kind of lubricant to use. See Recommended Fluids and Lubricants on page 6-12. 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 rear axle, variations in the readings can be caused by factory fill differences between the minimum and maximum fluid volume. 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. 5-47 Suburban LTZ (A) Drain Plug (B) Filler Plug