
Beyond the standard transfer case and rear differential every Sierra 4x4 has, AT4X trims add a front locking differential that sees real load during technical off-road driving. That's one more fluid-filled component that needs periodic attention beyond what a standard AT4 or work-trim 4x4 requires.

If you wheel an AT4X regularly through water or mud, cut the standard interval roughly in half across all three fluid-filled components.

Any Sierra that sees water crossings pushes the same moisture exposure onto rotors that it does onto diff and transfer case housings. GEOMET-coated rotors resist the surface rust untreated OEM rotors develop after repeated wet-condition off-roading.
Learn more in our Ghost Rotors Sierra brake kits.
GEOMET-coated rotors resist corrosion from water crossings and mud.
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