Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
316 Vehicle Care
Gas Engines
Tire sizeTire air pressure kPa (psi)
LT215/85R16E 480 (70)
225/70R19.5F 590 (85)
225/70R19.5G 590 (85)
For the 3.0L diesel engine, see “VIN
and Weight Rating Plate” under
Vehicle Identification Number (VIN)
0 383.
For the 5.2L diesel engine, see
“VIN, Weight Rating, and
Greenhouse Gas (GHG) Emissions
Plate” underVehicle Identification
Number (VIN) 0383.
For gas engines, see “Vehicle
Certification and Greenhouse Gas
(GHG) Emissions Plate” under
Vehicle Identification Number (VIN)
0 383.
See “Tire Load and Inflation Table”
under Tire Pressure 0322.
{Warning
Insufficiently inflated or worn-out
tires are highly dangerous as they
easily skid and can even burst.
Should they burst, the tires may
burn and this could cause a fire in
the vehicle.
If you drive on under-inflated or
flat tires, the wheel studs will be
placed under excessive stress.
Under such conditions, the bolts
may break and the wheel may
detach from the vehicle, possibly
causing an accident.
(Continued)
Warning (Continued)
Over-inflated tires result in a
harsh ride and are likely to cause
damage to the cargo.
Under-inflated tires build up heat
and could burst. Always keep the
tires of your vehicle adjusted at
the standard air pressures.
You and others could be seriously
injured.
There should not be a difference
tires on a dual-tire wheel.
It is not easy to visually identify an
under-inflated dual-wheel tire or low
aspect ratio tire (aspect ratio at
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
354 Service and Maintenance
How to check: This operation could
be difficult and you may choose to
have this done at your dealer
Service Department.
1. Turn the engine control switch to
the "ON" position (not to start the
engine), and press the brake pedal
several times.
2. Check for the noisy sound of the
electric vacuum pump inside the
instrument panel at the same time
as vacuum warning buzzer sound,
and check that the brake low
vacuum warning light comes on.
3. Then, after you start the engine,
the main vacuum pump driven by
the engine will start running. If the
electric vacuum pump operation
(noisy sound) and the vacuum
warning buzzer stop, and the brake
low vacuum warning light goes off
thereafter, the operation is normal.
4. If you cannot hear the noisy
sound of the electric vacuum pump,
check the electrical wiring and
repair as necessary. If it cannot be
repaired, replace the electric
vacuum pump.20. BRAKE FLUID :
Check the fluid
in the brake fluid reservoir every
12 000 km (7,500 miles) and replace
fluid every 48 000 km
(30,000 miles).
21. BRAKE LINE AND HOSES :
Check lines and hoses for proper
hook-up, binding, leaks, cracks,
chafing, etc. every 48 000 km
(30,000 miles). Any questionable
parts should be replaced or repaired
at once. When rubbing or wear is
noted on lines or hoses, the cause
must be corrected at once.
22. HYDRAULIC UNIT : Change
every 10 years.
23. DIFFERENTIAL GEAR OIL :
Replace lubricant every 48 000 km
(30,000 miles) or every 24 months.
Check lubricant level every
12 000 km (7,500 miles) or every
12 months, and add lubricant to
within 0 to 10 mm (0 to 0.4 inch) of
the bottom edge of the filler hole if
necessary. 24. POWER STEERING FLUID :
Replace power steering fluid every
24 months or 60 000 km
(37,500 miles), whichever occurs
first.
25. STEERING WHEEL FREE
PLAY :
Check steering wheel free
play after the first 1 040 km
(650 miles) and then every
10 400 km (6,500 miles).
Steering wheel free play
10-50 mm (0.39-1.97 in)
26. STEERING GEAR BOX
TORQUE : Retighten the fixing bolts
of the steering gear box to the
specified torque every 48 000 km
(30,000 miles). Specified tightening
torque.
Steering gear box tightening torque
102 Y(75 lb·ft)
27. DRIVESHAFT FLANGE
TORQUE : Check the fixing bolts of
driveshaft flange for looseness or
damage first 12 000 km
(7,500 miles). Retighten the fixing
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Service and Maintenance 355
bolts to the specified torque every
24 000 km (15,000 miles). Specified
tightening torque.Driveshaft flange tightening torque
103Y(76 lb·ft)
28. LEAF SPRING U-BOLT
TORQUE : Tighten the U-Bolt nuts
to the specified torque at 1 040 km
(650 miles), 12 000 km (7,500 miles)
and thereafter each 24 000 km
(15,000 miles). Specified tightening
torque.
Leaf spring U-bolt nut tightening torque
Front 127 Y(94 lb·ft)
Rear 177 Y(131 lb·ft)
29. WHEEL NUT TORQUE : Check
tires for excessive or abnormal
wear, or damage. Also check tire
inflation pressures and adjust. Be
sure wheels are not bent or cracked
and that wheel nuts have been
tightened to the specified torque at
1 040 km (650 miles) and then every
12 000 km (7,500 miles). Wheel nut tightening torque
500Y(362 lb·ft)
30. KING PIN : Lubricate the grease
fitting on the king pins every
12 months or 12 000 km
(7,500 miles) whichever occurs first.
31. DRIVESHAFT : Lubricate the
grease fitting on each universal joint
and spline coupling at 12 months or
24 000 km (15,000 miles) whichever
occurs first.
32. WHEEL HUB BEARING
GREASE : Clean and repack front
wheel bearings at every brake
relining or 48 000 km (30,000 miles)
whichever comes first.
33. ACCESSORY DRIVE BELT :
Replace the belt that drives the A/C
compressor every 160 000 km
(100,000 miles).
34. AIR CONDITIONER BLOWER
FILTER : The air conditioner blower
filter should be removed and
cleaned once a month.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
366 Service and Maintenance
25. Automatic Transmission
Fluid :Check the automatic
transmission fluid level at each
engine oil change and replace fluid
every 48 000 km (30,000 miles). Do
not overfill.
26. Differential Gear Oil : Replace
lubricant every 48 000 km
(30,000 miles). Check lubricant level
every 16,000 km (10,000 miles) or
every 12 months, and add lubricant
to within 0 to 10 mm (0 to 0.4 inch)
of the bottom edge of the filler hole
if necessary.
27. Power Steering Fluid :
Replace power steering fluid every
24 months or 48 000 km
(30,000 miles), whichever occurs
first.
28. Power Steering Oil Hoses :
Replace power steering oil hoses
every 24 months or 80 000 km
(50,000 miles), whichever occurs
first.
29. Steering Wheel Free Play :
Check steering wheel free play after
the first 1 040 km (650 miles) and
then every 10 400 km (6,500 miles). Steering wheel free play
10-50 mm (0.39-1.97 in)
30. Steering Gear Box Torque :
Retighten the attaching bolts of the
steering gear box to the specified
torque every 12 months or every
32 000 km (20,000 miles) whichever
occurs first. Steering gear box tightening torque
103 Y(76 lb·ft)
31. Driveshaft Flange Torque :
Check the fixing bolts of driveshaft
flange for looseness or damage
after the first 16 000 km
(10,000 miles). Driveshaft flange tightening torque
103Y(76 lb·ft)
32. Driveshaft Lubrication :
Lubricate the grease fitting on the
center bearing, as well as each
universal joint and spline coupling
every 12 months or 16 000 km
(10,000 miles) whichever occurs
first. 33. Leaf Spring U-bolt Torque :
Tighten the U-Bolt nuts to the
specified torque after the first
1 040 km (650 miles), thereafter
every 16 000 km (10,000 miles).
Model Leaf spring U-bolt nut tightening torque
Front Rear
3500HD 127 Y
(94 lb·ft) 177
Y
(131 lb·ft)
4500HD 127 Y
(94 lb·ft) 177
Y
(131 lb·ft)
4500XD 196 Y
(145lb·ft) 177
Y
(131 lb·ft)
5500HD, 5500XD 196
Y
(145lb·ft) 284
Y
(209 lb·ft)
34. Wheel Nut Torque : Check tires
for excessive or abnormal wear,
or damage. Also check tire inflation
pressures and adjust.
Be sure wheels are not bent or
cracked and that wheel nuts have
been tightened to the specified
torque after the first 1,040 km
(650 miles) and then every