Fluid - Transfer Case: Service and Repair
FLUID FILL1. Remove the fill plug from the rear of the transfer case and check the fill level.
^ If the fluid is below the specified level, fill with Motorcraft MERCON Multi-Purpose Automatic Transmission Fluid XT-2-QDX or -DDX or equivalent MERCON fluid.
CAUTION: If the proper fill procedures are not followed, transfer case failure can result.
NOTE: The fluid level should be just below the fill plug.