2008 GMC Acadia Owner's Manual - Page 358

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. 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 will 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. Rear Drive Module 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 (A) Filler Plug (B) Drain Plug 5-44