"D" - Operating In Dusty Conditions

SPECIAL OPERATING CONDITION "D" - Operating in dusty conditions such as unpaved or dusty roads

Every 5,000 miles
- Inspect wheels and related components for abnormal noise, wear, looseness or drag.
- Rotate tires, inspect tire wear and measure tread depth. If equipped with the dual rear wheels, rotate front wheels when specified, rear wheels only if unusual wear is noted.

Every 5,000 miles or 6 months
- Inspect and lubricate U-joints.
- Change engine oil and replace oil filter.

Every 5,000 miles or 6 months or 200 engine hours
- Change engine oil and replace oil filter.

Every 30,000 miles
- Change automatic transmission/transaxle fluid (Except on 6R80 and TorqShift transmissions).
- Replace front wheel bearing grease/grease seals if non-sealed bearings are used (2WD vehicles).

Every 50,000 miles
- Change manual transmission fluid.
- Change rear axle (E-450 and F-450/550 only).

Every 60,000 miles
- Change transfer case fluid.

Inspect frequently, service as required
- Cabin air filter (if equipped).
- Engine air filter.