Transmission
On all light duty vehicles, check transmission fluid level every 12 months or 7500 miles. On heavy duty vehicles, check fluid level every 12 months or 6000 miles. Periodic draining and refilling is not required.
Transfer Case
Check transfer case fluid at every oil change or every 12 months. Under severe conditions, check more frequently.
Transmission & Transfer Case
Remove filler plug. Fluid should be level with bottom of filler plug hole. Add as necessary.