
Care should be taken to avoid sudden accelerations when both drive
wheels are on a slippery surface.
WARNING:Sudden accelerations on slippery surfaces could
cause the wheels to spin, the vehicle to turn sideways on a
crowned road surface or in a turn, possibly resulting in loss of vehicle
control and personal injury.
Some drive axles have a driver-controlled differential lock. The
differential lock can lock or unlock the differential when the vehicle is
moving or stopped. When extra traction is required, the differential lock
provides full power to both axles.
When the differential is locked, the vehicle’s turning radius increases
(vehicle “under-steers”).
The differential can be locked or unlocked when the vehicle is moving at
a constant speed of under 25 mph (40 km/h) and while the wheels are
not slipping. The differential must not be locked when the vehicle is
traveling down steep grades and traction is minimal.
Note:Never use the differential lock at vehicle speeds above 25 mph
(40 km/h).
The differential lock and differential lock light automatically disengage at
speeds above 25 mph (40 km/h). The differential lock remains off until
either the vehicle is restarted or the differential lock switch is turned off
then back on.
Axle conversions
It is not recommended, or approved, for axle conversions to be
performed. However, it is understood that, on occasion, aftermarket
add-on axles are installed by others on the truck chassis which allow
operator control for weight transfer from other axles (i.e., air lift axles).
WARNING:When operating a loaded vehicle, the driver must
keep all adjustable axles on the ground at all times, supporting
their share of the vehicle’s load. Failure to do so can overload other
axles, tires, wheels, springs, steering components, brakes and frames,
resulting in early component failure, loss of vehicle control, possible
property damage and personal injury.
Driving
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If evidence of corrosion is found (usually at the pipe connections), use a
wire brush to clean the inside of the pipes and inside the rubber hoses.
If the intake pipes are pitted at the joint ends, use MotorcraftSilicone
Gasket and Sealant TA-30 to seal the joints. Be certain that no excess
material is on the inside of the pipes that can be pulled into the engine.
If the service condition of the pipes, hoses or clamps is questionable,
replace the defective part(s).
Be sure that prior to reassembly all dust and debris has been cleaned out
of the pipes and couplings with a clean, damp rag.
WARNING:When performing maintenance to any turbocharged
engine with engine air inlet piping disconnected, keep loose
clothing, jewelry and long hair away from the engine air inlet piping. A
turbocharger compressor air inlet protective shield should be installed
over the turbocharger air inlet to reduce the risk of personal injury or
death.
Steering - general inspection
•Ask your service technician to examine the steering mechanism. Only
minor adjustments may be necessary.
•Check tie rod, drag link end clamp bolts and ball joints. They must be
tight.
•Check for installation and spread of cotter pins and tightness of nuts
at both ends of the tie rod and drag link.
•Check that pitman arm (steering arm at steering gear) mounting is
tight and locked. Check system for leaks or hose chafing. Repair at
once.
•Maintain proper steering gear and power steering pump lubricant
levels.
•Regularly inspect steering column joint bolts and steering linkage,
particularly for body-to-chassis clearance.
Note:Have any steering problems corrected at once by a qualified
service technician.
WARNING:Failure to maintain the steering system in proper
condition can cause reduced steering ability resulting in property
damage, personal injury or death.
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Tightening steering column joint bolts
As a good maintenance practice, it is recommended that steering column
joint bolts be checked for tightness every 60,000 miles (96,000 km) or
annually, whichever occurs first. DO NOT OVERTIGHTEN.
Power steering hydraulic system
Whenever the power steering’s hydraulic system has been drained and
refilled for any reason, air must be bled from the system before returning
the vehicle to service. Failure to properly bleed the hydraulic system can
result in degradation of power system performance.
Consult your dealer who is aware of the proper procedures for filling and
bleeding the system.
OPENING THE HOOD
The hood and fenders are held in position by a latch located on each
fender.
WARNING:The parking brake must be fully set before opening
the hood or possible personal injury may occur.
WARNING:To reduce the risk of the possibility of personal
injury, never stand beneath the hood when it is being raised or
lowered.
WARNING:If you must leave the engine running while checking
under the hood, do not allow any loose clothing, jewelry, hair or
other items to get near moving engine components or possible personal
injury may occur.
To open the hood:
1. Set the parking brake, shift into N (Neutral) (automatic transmission)
or 1 (First) (manual transmission) and turn the engine off.
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How fail-safe cooling works
If the engine begins to overheat:
•The engine coolant temperature gauge will move to the red (hot)
area.
•The message center will indicate the engine is overheating.
•The service engine soon
indicator will illuminate.
If the engine reaches a preset over-temperature condition, the engine
will automatically switch to alternating cylinder operation. Each disabled
cylinder acts as an air pump and cools the engine.
When this occurs the vehicle will still operate. However:
•The engine power will be limited.
•The air conditioning system will be disabled.
Continued operation will increase the engine temperature and the engine
will completely shut down, causing steering and braking effort to
increase.
Once the engine temperature cools, the engine can be restarted. Take
your vehicle to an authorized dealer as soon as possible to minimize
engine damage.
When fail-safe mode is activated
You have limited engine power when in the fail-safe mode, so drive the
vehicle with caution. The vehicle will not be able to maintain high-speed
operation and the engine will run rough. Remember that the engine is
capable of completely shutting down automatically to prevent engine
damage; therefore:
1. Pull off the road as soon as safely possible and turn off the engine.
2. Arrange for the vehicle to be taken to an authorized dealer.
3. If this is not possible, wait a short period for the engine to cool.
4. Check the coolant level and replenish if low.
WARNING:Never remove the coolant reservoir cap while the
engine is running or hot.
5. Re-start the engine and take your vehicle to an authorized dealer.
Driving the vehicle without repairing the engine problem
increases the chance of engine damage. Take your vehicle to an
authorized dealer as soon as possible.
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Exhaust System:
•Inspect for leaks at various joint connections and loose clamps.
•Perform a visual inspection for cracks or holes in the muffler and tail
pipe.
•Always use the recommended parts when items need to be replaced.
•Do not change the tail pipe elbow or offset tail pipe orientation from
the standard position as originally received.
•To avoid abnormal changes in vehicle sound levels, it is necessary for
the owner to perform inspections and necessary maintenance at the
intervals shown in theScheduled Maintenance Guidechapter.
POWER STEERING FLUID
Check the power steering fluid level using the following procedure:
1. Set the parking brake, shift into N (Neutral) (automatic transmission)
or 1 (First) (manual transmission) and turn the engine off.
2. Open the hood.
3. Clean the top of the power steering fluid reservoir.
4. Remove the dipstick from the reservoir and wipe the dipstick clean.
5. Reinstall the dipstick. Remove it again and check the fluid level.
•Check the COLD side of the
dipstick if the fluid is cool or
warm to the touch
(approximately 68°-120°F
[20°-49°C]); the fluid level should
be within the FULL range. If
necessary, add fluid in small
amounts, continuously checking
the level, until it reaches the proper level.
•Check the HOT side of the
dipstick if the fluid is too hot to
touch (approximately 176°–230°F
[80°-110°C]); the fluid level
should be within the FULL range.
If necessary, add fluid in small
amounts, continuously checking
the level, until it reaches the
proper level.
Whenever the dipstick is installed, make sure it is properly seated and
tightened securely.
ADD MAX. COLDFULL
ADD MAX. HOTFULL
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The fluid level can also be checked by looking at the see-through plastic
reservoir. Make sure that the fluid is within the minimum and maximum
fluid range as marked on the reservoir.
To avoid damage to the power steering system,do notoperate the
vehicle with a low power steering fluid level.
Note:Refer toLubricant specificationsin this chapter for the proper
fluid type if adding fluid is necessary. A low fluid level may indicate a
leak in the power steering system. Inspect the power steering system
and repair the leak or see your dealer or a qualified technician for
service. Refer to theScheduled Maintenance Guidechapter for the
recommended service intervals.
BRAKE FLUID
Check and refill the Full Power brake fluid reservoir using the following
procedure. Refer to theScheduled Maintenance Guidechapter for the
service interval.
1. Clean the reservoir caps before removal to prevent dirt or water from
entering the reservoir.
2. Visually inspect the fluid level; it should be at the bottom of the fill
ports.
3. Add brake fluid, if necessary, from a clean, unopened container until
the level reaches the bottom of the fill ports. Do not fill above this line.
Only use a DOT 3 brake fluid certified to meet manufacturer
specifications. Refer toLubricant specificationsin this chapter.
WARNING:Brake fluid is toxic. If brake fluid contacts the eyes,
flush eyes with running water for 15 minutes. Seek medical
attention if irritation persists. If taken internally, drink water and
induce vomiting. Seek medical attention immediately.
WARNING:If you use a brake fluid that is not DOT 3, you will
cause permanent damage to your brakes.
WARNING:Do not let the reservoir for the master cylinder run
dry. This may cause the brakes to fail.
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Component Lubrication typeViscosity / Ambient
temperature / NotesEquivalent Ford part
name / number
Eaton-Spicer axle,
Spicer axle - Front
axle wheel bearing
grease, tie rod ends,
drag link, kingpin and
bushingEP2 Lithium
complex-based moly
grease (or equivalent)
GC/LB NLGI #2
multi-purpose lithium
complex greaseNote:Eaton-Spicer
and Meritor Easy Steer
axles: With chassis
load on axle, force
grease through thrust
bearings; then with
axle lifted clear of the
floor, force grease
between kingpin and
bushing surfaces.MotorcraftPremium
Long Life Grease /
XG-1-C
Steering
Power steering fluid MERCONV ATF — MERCONV/
XT-5-QMC; XT-5-QM;
XL-14
Steering gear Ross TAS
- Output Seal, Steering
column U-joints / slip
jointGC/LB NLGI #2 lithium
complex-based moly
grease or
multi-purpose lithium
complex grease— MotorcraftPremium
Long Life Grease /
XG-1-C
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Axle model Pints (Liters)*
RS-19–220 30.0 (14.0)
RS-19–223 29.0 (13.0)
RS-21–145 32.3 (15.3)
RS-21–160 39.0 (18.0)
RS-21–230 38.9 (18.4)
RS-23–160 39.5 (18.7)
RS-23–161 37.2 (17.6)
RS-23–180 47.3 (22.4)
RS-23–186 47.3 (22.4)
RS-23–240 37.4 (17.7)
RS-23–380 63.6 (30.1)
*Oil capacities are for standard track axles that have been measured at
various common drive pinion angles. The quantities listed include enough
oil for both wheel ends. These capacities change if the track or the drive
pinion angle is different.
Engine coolant and oil
Engine Engine coolant1,2Engine oil1
Diesel 26.0 quarts (24.6L) Refer to engine operator’s manual
Gas26.3 quarts (24.9L) 7.0 quarts (6.6L) (includes filter
change)
1Quantities listed are approximate.
2Add the coolant type originally equipped in your vehicle.
Power steering system
Steering gear Power steering fluid volume
TAS40 17.6 pints
TAS66 18.4 pints
Note:Capacities may be increased if the vehicle is equipped with a
cooler. Always check to make sure the fluid level is in the acceptable
range.
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