Ranger 4WD V6-245 4.0L VIN X SFI (1999)
Fluid - Transfer Case: Fluid Type Specifications
CAUTION: If the proper fill procedures are not followed, transfer case failure can result.
NOTE: Fluid level should be just below the fill plug.
Remove the fill plug from the rear of the transfer case, and check the fill level.
-If the fluid is below the level, fill with Motorcraft MERCON Multipurpose Automatic Transmission Fluid WSP-M2C185-A or MERCON equivalent
fluid.