Page 457 of 475

Normal scheduled maintenance*
At every oil change
interval as indicated by
the information displayChange engine oil and filter.**
Rotate tires, inspect tire wear and measure
tread depth.
Perform multi-point inspection
(recommended).
Inspect automatic transmission fluid level (if
equipped with dipstick). Consult dealer for
requirements.
Inspect brake pads, shoes, rotors, drums,
brake linings, hoses and parking brake.
Inspect engine cooling system strength and
hoses.
Inspect exhaust system and heat shields.
Inspect front axle and U-joints. Lubricate if
equipped with grease fittings (Four–wheel
drive vehicles).
Inspect half-shaft boots (if equipped).
Inspect steering linkage, ball joints,
suspension, tie-rod ends, driveshaft and
U-joints. Lubricate if equipped with grease
fittings.
Inspect wheels and related components for
abnormal noise, wear, looseness or drag.
*Do not exceed one year or 10000 miles (16000 kilometers) between
service intervals.
**Reset your Intelligent Oil-Life Monitor after each engine oil and filter
change. See the Instrument Cluster chapter.
456Scheduled Maintenance
2015 Navigator (nav)
Owners Guide gf, 2nd Printing, December 2014
USA (fus)
Page 462 of 475

SPECIAL OPERATING CONDITIONS
If you operate your vehicleprimarilyin any of the following conditions,
you need to perform additional maintenance as indicated. If you
occasionally operate your vehicle under any of these conditions, it is
not necessary to perform the additional maintenance. For specific
recommendations, see your dealership service advisor or technician.
Perform the services shown in the following tables when specified or
within 3000 miles (4800 kilometers) of the OIL CHANGE REQUIRED
message appearing in the information display.
Example #1: The OIL CHANGE REQUIRED message comes on at
28751 miles (46270 kilometers); perform the 30000 mile (48000
kilometer) automatic transmission fluid replacement.
Example #2: The OIL CHANGE REQUIRED message has notcome on,
but the odometer reads 30000 miles (48000 kilometers); perform the
engine air filter replacement. (i.e., Intelligent Oil-Life Monitor was reset
at 25000 miles [40000 kilometers].)
Towing a trailer or using a camper or car-top carrier
As required Change engine oil and filter as indicated by the information display and perform services
listed in the Normal Scheduled Maintenance
chart.
Inspect frequently,
service as required Inspect and lubricate U-joints.
See axle maintenance items under
Exceptions.
Every 60000 miles
(96000 km) Change transfer case fluid (Four–wheel drive
vehicles).
Scheduled Maintenance
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Owners Guide gf, 2nd Printing, December 2014
USA (fus)
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Extensive idling or low-speed driving for long distances as inheavy commercial use (such as delivery, taxi, patrol car or livery)
As required Change engine oil and filter as indicated by the information display and perform services
listed in the Normal Scheduled Maintenance
chart.
Inspect frequently,
service as required Replace engine air filter.
Every 60000 miles
(96000 km) Replace spark plugs.
Change transfer case fluid (Four–wheel drive
vehicles).
Operating in dusty or sandy conditions such as unpaved or
dusty roads
Inspect frequently,
service as required Replace engine air filter.
Every 5000 miles
(8000 km) Inspect the wheels and related components for
abnormal noise, wear, looseness or drag.
Rotate tires, inspect tires for wear and
measure tread depth.
Every 5000 miles
(8000 km) or six
months Change engine oil and filter.
*
Every 60000 miles
(96000 km)
Change transfer case fluid (Four–wheel drive
vehicles).
*Reset your Intelligent Oil-Life Monitor after each engine oil and filter
change. See the Instrument Cluster chapter.
462Scheduled Maintenance
2015 Navigator (nav)
Owners Guide gf, 2nd Printing, December 2014
USA (fus)
Page 464 of 475
Off-road operation
Inspect frequently,
service as required Inspect steering linkage, ball joints and
U-joints. Lubricate if equipped with grease
fittings.
Replace engine air filter.
Every 5000 miles
(8000 km) or six
months Change engine oil and filter.
*
Inspect wheels and related components for
abnormal noise, wear, looseness or drag.
Rotate tires, inspect tires for wear and
measure tread depth.
Every 30000 miles
(48000 km) Replace front wheel bearing grease and grease
seals if non-sealed bearings are used (2WD
vehicles).
Every 60000 miles
(96000 km) Change transfer case fluid (Four–wheel drive
vehicles).
*Reset your Intelligent Oil-Life Monitor after each engine oil and filter
change. See the Instrument Cluster chapter.
Scheduled Maintenance 463
2015 Navigator(nav)
Owners Guide gf, 2nd Printing, December 2014
USA (fus)