2011 Chevrolet Suburban 1500 Owner's Manual - Page 416

10-32 Vehicle Care How to Check Lubricant To get an accurate reading, the vehicle should be on a level surface. . Also, if a vehicle has just been driven before checking the fluid level, it may appear lower than normal because fluid has traveled out along the axle tubes and has not drained back to the sump area. Therefore, a reading taken five minutes after the vehicle has been driven will appear to have a lower fluid level than a vehicle that has been stationary for an hour or two. Remember that the rear axle assembly must be supported to get a true reading. For the 1500 series, the proper level is from 1.0 mm to 19.0 mm (0.04 in to 0.75 in) below the bottom of the fill plug hole, located on the rear axle. Add only enough fluid to reach the proper level. For the 2500 series, the proper level is from 0 mm to 13 mm (0 in to 1/2 in) below the bottom of the fill plug hole, located at the front of the axle. Add only enough fluid to reach the proper level. . 1500 Series 2500 Series