My 2020 has had "service 4WD" on the DIC multiple times. I took the truck to the dealer and they said they checked the levels in the front and rear diffs and they were fine. Truck still puts up "service 4WD". In the most recent DIC's the truck is in 2WD with the 2WD in orange on the dash, the first time the truck was in auto with auto in orange. This got me think this "service 4WD" is looking at both diffs. I finally put the truck up on my lift and checked the front and rear diffs. Both are about 3/8 below the fill plug hole. The owners manual from front and rear diff fluid type says see dealer. My 2013 LML took a 75w-90 synthetic with limited slip additive. How full should the Diffs be? I filled the 2013 to the bottom of the fill plug and never had an issue. What type and weight oil should be used in the front and rear diffs? Both look and feel the same clear synthetic oil. Thanks for the info.