Time: approx 15 minutes

Difficulty - easy

Cost - $20-40

WHY

The transfer case is mounted directly to the back of the transmission. Constant rotation of at least some internal parts is always taking place. Wear, 4X4 use, and venting to the atmosphere can bring in moisture and contaminants leading to gasket failure and corrosion. Fresh fluid keeps seals and metal parts happy.

WHEN

Replace your transfer case fluid every 30-60,000 miles. The range depends on factors such as off-roading, snow, towing, temperature extremes, etc.

METHOD

The fluid exchange is simply a drain and refill. The capacity is 1.45 qts Mercon LV ATF or equivalent.

The transmission and transfer case both use Mercon LV automatic transmission fluid. Ford previously ran XL-12 transfer case fluid in their electronic shift transfer cases, but has since superseded the fluid with Mercon LV as a substitute. Having the same fluids in the transmission and transfer case prevents mixing of incompatible fluids should an internal leak occur between the two assemblies.

Watch the video below to see how the transfer case fluid was changed on a 2016 Ford F150 pickup.