5. Follow one of the simple calculations in order to determine fuel
economy:
•Divide total miles traveled by total gallons used.
•Multiply liters used by 100, then divide by total kilometers traveled.
Keep a record for at least one month and record the type of driving (city
or highway). This will provide an accurate estimate of the vehicle’s fuel
economy under current driving conditions. Additionally, keeping records
during summer and winter will show how temperature impacts fuel
economy. In general, lower temperatures give lower fuel economy.
Driving style - good driving and fuel economy habits
Give consideration to the lists that follow and you may be able to change
a number of variables and improve your fuel economy.
Habits
•Smooth, moderate operation can yield up to 10% savings in fuel.
•Steady speeds without stopping will usually give the best fuel
economy.
•Anticipate stopping; slowing down may eliminate the need to stop.
•Sudden or hard accelerations may reduce fuel economy.
•Slow down gradually.
•Driving at reasonable speeds (traveling at 55 mph [88 km/h] uses 15%
less fuel than traveling at 65 mph [105 km/h]).
•Using the air conditioner or defroster may reduce fuel economy.
•Resting your foot on the brake pedal while driving may reduce fuel
economy.
Conditions
•Carrying unnecessary weight may reduce fuel economy.
•Fuel economy may decrease with lower temperatures during the first
8–10 miles (12–16 km) of driving.
•Flat terrain driving improves fuel economy over hilly roads.
•Transmissions give their best fuel economy when operated in the top
cruise gear and with steady pressure on the accelerator.
•Close windows for highway driving.
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DIESEL PARTICULATE FILTER (DPF)
Your vehicle is equipped with a diesel particulate filter (DPF), as part of
the after-treatment exhaust system, to trap soot and other large particles
produced by the engine combustion process. The soot that accumulates
in the filter must be periodically reduced to ash to prevent excessive
exhaust restriction. The soot reduction process, also known as “filter
regeneration,” is generally performed automatically by your engine and
after-treatment system.
WARNING:The normal operating temperature of the exhaust
system is very high. Never work around, or attempt to repair,
any part of the exhaust system until it has cooled. Use special care
when working around the diesel particulate filter. The DPF heats up to
a high temperature after only a short period of engine operation, and
can remain hot even after the engine is turned off. Failure to follow
these instructions may result in serious personal injury.
Diesel particulate filter regeneration
Under most operating conditions, DPF regeneration will be transparent
to the operator. A small increase in engine/turbo sound-level is normal
during filter regeneration. If, however, your engine is operated for
extended periods of time under one of the following conditions, operator
assistance may be required to facilitate the filter regeneration process:
•Vehicle is operated in stop-and-go traffic and/or maintains low speeds
as in a city/delivery driving
•Engine is started and shut-off frequently
•Vehicle payload is relatively light
•Vehicle is regularly operated in cold ambient temperatures (i.e. below
0°F [-18°C])
Diesel Particulate Filter Four–Level Loading Chart
Level/Lamp status Filter status Requested action
Level 1
DPF lamp solidRegeneration required. Drive on highway at
highway speedsOR
start “parked
regeneration” to
prevent loss of engine
performance. Level 2
DPF lamp flashing
(once per second)Nearly full. Engine
performance is limited.
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SUSPENSION INSPECTION
Note:Do not adjust air suspension height to any setting other than the
specified setting. Altering the height setting will change the driveline
angle and may result in unwarrantable component damage, such as
transmission component damage.
Verify drive axle air suspension height and height control valve
performance at engine lube oil change intervals.
Periodically:
•Check condition of spring leaves for evidence of fatigue, bending or
breakage.
•Check condition of suspension mounting brackets and bushings.
•Check that torque rod mounting fasteners are tight.
•Check to be sure the suspension alignment is maintained at all times.
•Check U-bolts after the chassis has been operating under load for
1,000 miles (1,600 km) or six months, whichever comes first, the
U-bolt nuts must be re-torqued. The U-bolt nuts thereafter must be
re-torqued every 36,000 miles (58,000 km). The U-bolt and nut
threads and seats should be cleaned and lubricated to ensure a “like
new” condition when re-torquing.
Note:See theU-bolt nut torquechart later in this section.
Supporting your vehicle for service
When performing service repairs on your vehicle, first prepare the
vehicle by doing the following:
1. Park the vehicle on a level concrete floor.
2. Set the parking brake and block the wheels to prevent the vehicle
from moving.
3. Select a jack with a rated capacity sufficient to lift and hold up the
vehicle.
4. Raise the vehicle with the jack applied to the axle(s). DO NOT use the
bumper as a lifting point.
5. Support the vehicle with floor stands under the axle(s). If the axle or
the suspension are being serviced, support the vehicle with floor stands
under the frame side-members, preferably between the axles.
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WARNING:Do not use a jack when working under a vehicle. It
may give way, causing the vehicle to fall and result in property
damage, personal injury or death. Always use floor stands to support
the vehicle.
FRAME AND TOW HOOKS
Your vehicles chassis is manufactured with frame rails of either HSLA
steel or heat-treated steel. Each must be handled in a specific manner to
ensure maximum service life. Before attempting frame repair or
modification, consult the service manual or your dealer.
It is important, particularly on vehicles where the tow hooks are used
frequently, to inspect the front and rear tow hooks for damage or a loose
mounting.
SPRING U-BOLT CHECKS
Check U-bolt nuts and re-torque every 36,000 miles (58,000 km) after
initial 1,000 miles (1,600 km) re-torque. The U-bolt and nut threads and
seats should be cleaned and lubricated to ensure peak condition when
re-torqued.
U-bolt nut torque
Suspension ft-lb N•m
Front axle – 8500 lb (3856 kg) 180-200 244-271
Front axles – 10000 lb (4536 kg) and higher 260-300 353-407
Rear axle with multi-leaf 260-300 353-407
Rear axle with IROS air suspension 370-400 502-542
Rear axle with Hendrickson air suspension 400–450 542–610
See air suspension U-bolt re-torquing and installation information below.
Air suspension U-bolt checks and re-torquing procedures
1. Inspect the threads of the U-bolt and nut for rust and debris. Clean
the threads if contaminated.
2. Using a torque wrench, determine if any nuts can be turned with a
force below the specified torque.
3. Using the lowest discovered torqued nut as a starting point, retighten
the nuts using the sequence listed underAir suspension U-bolt and
U-bolt nut installation.
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WARNING:Use only the same type and style wheels and
mounting hardware to replace original parts. Failure to do so
may result in an assembly that looks fine, but does not fit together
properly. This could possibly cause wheel or fastener failures which
could result in property damage, personal injury or death.
Note:Do not attempt to mix stud-piloted wheels or fasteners with
hub-piloted wheels or fasteners.
Note:Do not change from aluminum wheels to steel wheels or
vice-versa without changing the mounting hardware required or, with
flange-nut mounting systems, changing the hub and stud assembly.
WHEEL NUT TORQUE
Size Nut mountingTorque
ft-lb N•m
22 mm Flange 450–500 610–678
Note:Do not use lubrication on dry threads. Where excessive corrosion
exists, a light coat of lubricant on the first three threads of the stud bolt
is permitted. Keep lubricant away from:
•Hex nut and rim clamp contact surfaces.
•Cap nut ball face and ball seat on the disc wheel.
•Flange nut washer surface and flat on the disc wheel.
TIRE INFORMATION
Inflation
WARNING:Always maintain your tires in good condition.
Frequently check and maintain correct inflation pressures as
specified by tire manufacturers. Inspect periodically for abnormal wear
patterns and repair/replace cut or broken tire casing. Always use
experienced, trained personnel with proper equipment and correct
procedures to mount or remove tires and wheels. Failure to adhere to
these warnings could result in wheel or tire malfunction, damage to
your vehicle, personal injury, or death.
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Stay out of the trajectory (1) as indicated in the illustration.
WARNING:Do not mount tube type tires on tubeless wheels or
tubeless tires on tube type wheels. To do so could result in tire
or wheel failure and cause property damage, personal injury or death.
Preserving proper inflation pressure is a very important maintenance
practice to insure safe vehicle operation and long life for the tires.
Failure to maintain correct inflation pressure may result in sudden tire
destruction, improper vehicle handling, and may cause rapid and
irregular tire wear. Therefore, inflation pressures should be checked daily
and always before long distance trips.
Follow the tire manufacturer’s recommended cold inflation pressure for
the tire size, type, load range (ply rating) and axle loading typical for
your operation. (Each steer axle tire load will equal
1 2steer axle loading;
each drive tire load will be1 4the axle loading if fitted with four tires).
Checking inflation
Always check inflation pressure when tires are cold. Never bleed air from
hot tires to relieve normal pressure build-up. Normal increases in
pressure due to service conditions will be 10–15 psi (69–103 kPa), which
is allowable in truck tires.
Tires should be properly inflated to manufacturers recommended
pressure for the size and service load in which the vehicle is being used.
Refer to the specific tire manufacturer with which your vehicle is
equipped with for the latest information concerning service load and
inflation pressure.
It is particularly important to keep moisture from the inside of tires, and
proper selection of air compressor equipment, proper air line routing,
and the use of shop air dryers is strongly recommended to avoid
moisture in the high pressure air used for tire inflation.
Under-inflation
Tires should not be permitted to become under-inflated. Increased
flexing due to under-inflation causes heat build-up within the tire
components. This leads to reduced strength, breakdown of the rubber
compounds, and possible separation of the tire components (i.e., ply and
tread separation and reduced retreadability).
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Under-inflation is the primary cause of premature tire concerns including
sudden loss of air. In addition, low inflation causes an increase in rolling
resistance. This results in reduced fuel mileage, a loss in tread mileage,
and uneven wear due to increased tread movement. To determine proper
inflation refer to the tire manufacturer load/inflation guide which can be
found on the tire manufacturer website or at your local truck tire dealer.
Inspection
Check condition of tires for abnormal wear patterns, and proper inflation
pressures. Cut or broken tire casing must be repaired or replaced.
Tires should be inspected for the following conditions. If any are present,
the tire should be removed and repaired, retreaded or scrapped as the
condition indicates.
•Any blister, bump or raised portion anywhere on the surface of the
tire tread or sidewall (other than a bump made by a repair). These
indicate the start of internal separation.
•Any cut that reaches to the belt or ply cords, or any cut that is large
enough to grow in size and depth.
•Any nail or puncturing object.
•If any stone or object is held by a tread groove and is starting to drill
into the tread base, remove the object.
Proper tire inflation, toe-in adjustment, loads, and road speeds are
important factors governing tire mileage, steering ease and
maneuverability.
Loads
WARNING:Loading tires beyond their rated capacity decreases
tire life requiring more frequent replacement of tires.
Overloading creates an unsafe condition that may result in sudden air
loss from a tire failure resulting in an accident that could cause
property damage, personal injury or death.
Note:Your GAW/GVW rating is correct at the time of your vehicle
production, and reflects the exact rating of the tires specified. When
replacing tires be sure that the replacement tire load rating (listed in
pounds and kilograms on the tire sidewall) is the same or higher than
the tire that is removed. Failure to do so will adversely affect maximum
load carrying capacity. Tires with the same size specification do not
always have the same load specification.
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Transmission
Description Pints (Liters)
Allison 2000 Series 30.0 (14.2)*
Allison 3000 Series 37.6 (17.8)*
5–speed manual 12.5 (5.9)
6–speed manual 19.5 (9.2)
7–speed manual 22.0 (10.4)
*Total fluid capacity (dry transmission and torque converter).
Air conditioner refrigerant - r134a
This system uses PAG-type refrigerant oil.
Refrigerant fitting torque
Captured washer nut: 170–190 inch lb. (19–21 N•m)
Note:This system uses mineral-based refrigerant oil to lubricate o-rings
and fittings.
Fuel tanks
Standard tanks are listed as such; all other tanks available for your
vehicle are optional equipment.
Vehicle Tank type Gallons
(Liters)
F-650 Low Profile (standard), F-650
Dock HeightSingle, steel
rectangular35 (132)
F-650 Low Profile, F-650 Dock
Height (standard), F-750 Pick-up
and Delivery (standard), F-750
Severe Service (standard)Single, steel
rectangular45 (170)
F-650 Dock Height, F-750 Pick-up
and Delivery, F-750 Severe ServiceSingle, steel
rectangular50 (189)
F-650 Low Profile, F-650 Dock
Height, F-750 Pick-up and Delivery,
F-750 Severe ServiceSingle, steel
rectangular65 (246)
F-650 Dock Height, F-750 Pick-up
and Delivery, F-750 Severe ServiceSingle, steel
D-style65 (246)
F-650 Dock Height, F-750 Pick-up
and Delivery, F-750 Severe ServiceSingle, steel
D-style80 (302)
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