2005 Chevrolet Avalanche Owner's Manual - Page 385

How to Check Lubricant Front Axle When to Check and Change Lubricant It is not necessary to regularly check front 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. How to Check Lubricant 1. Remove the filler plug. 2. Add new fluid until the level is below the bottom of the filler plug hole, located on the transfer case. To get an accurate reading, the vehicle should be on a level surface. Refer to the Maintenance Schedule to determine what kind of lubricant to use. See Recommended Fluids and Lubricants on page 6-13. 3. Reinstall the filler plug. Use care not to overtighten the filler plug. To get an accurate reading, the vehicle should be on a level surface. 5-51