How to identify and service the front differential of a 2019-2023 GM 1500 4X4 vehicle. The fluid type and capacity will depend on the front axle provider;  AAM (American Axles Manufacturing) or GM with RPO codes SU4 and SU5 respectively. Applicable to the Sierra, Silverado, Yukon, Tahoe, and Suburban, 2019, 2020, 2021, 2022, and 2023  with the 1500 chassis.   

Heat and load exposure are the determining factors for service interval. Obviously, doing the service early and regular can minimize breakdown of the fluid, preventing gear-wear and contamination that lead to seal, bearing, and/or electrical component failure. In general, an interval of 30-60,000 miles is recommended with the range dependent on driving conditions, ie. heavy start/stop traffic, pulling a load, extensive 4X4 operation.