2004 Cadillac Escalade EXT Owner's Manual - Page 355

If the level is below the bottom of the filler plug hole, you may need to add some lubricant. When the differential is cold, add enough lubricant to raise the level from 1/2 inch (12 mm) to about 5/8 inch (18 mm) below the filler plug hole. When the differential is at operating temperature (warm), add enough lubricant to raise the level to the bottom of the filler plug hole. Headlamp Aiming 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. Your vehicle has a visual optical headlamp aiming system equipped with horizontal aim indicators. The aim has been preset at the factory and should need no further adjustment. This is true even though your horizontal aim indicators may not fall exactly on the "0" (zero) marks on their scales. 5-49