2007 GMC Acadia Owner's Manual - Page 431

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 502. 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. What to Use Refer to the Maintenance Schedule to determine what kind of lubricant to use. See Recommended Fluids and Lubricants on page 511. How to Check Lubricant Headlamp Aiming Headlamp aim has been preset at the factory and should need no further adjustment. However, if your vehicle is damaged in an accident, the headlamp aim may be affected. Aim adjustment to the low-beam headlamps may be necessary if oncoming drivers flash their high-beam headlamps at you (for vertical aim). If you believe your headlamps need to be re-aimed, it is recommend that you take the vehicle to your dealer/retailer for service. (A) Filler Plug (B) Drain Plug To get an accurate reading, the vehicle should be on a level surface. 431