2005 GMC Canyon Owner's Manual - Page 317

If the level is below the bottom of the filler plug hole, located on the rear axle, you will need to add some lubricant. Add enough lubricant to raise the level to the bottom of the filler plug hole. How to Check Lubricant What to Use See Recommended Fluids and Lubricants on page 6-13 to determine which kind of lubricant to use. Four-Wheel Drive Lubricant checks in this section apply to this vehicle. There are two additional systems that need lubrication. Transfer Case When to Check Lubricant Refer to the Maintenance Schedule to determine how often to check the lubricant. See Additional Required Services on page 6-6. 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, located on the transfer case, you'll need to add some lubricant. Remove the plug and add enough lubricant to raise the level to the bottom of the filler plug hole. Use care not to overtighten the plug. What to Use Refer to the Maintenance Schedule to determine what kind of lubricant to use. See Recommended Fluids and Lubricants on page 6-13. 5-45