40.00
Wheels and Tires
Specifications
Tire Pressure
Do not reduce the pressure of a hot tire if it exceeds
the specified pressure. In normal driving, tire temperature and inflation pressure increase. Increases of
10 to 15 psi (70 to 105 kPa) are common. Higher
pressures may be signs of overloading, underinflation, excessive speed, improper tire size, or any
combination of these factors, and must be checked
when the tire is cool.
IMPORTANT: The load and cold inflation pressure must not exceed the rim or wheel manufacturer’s recommendations, even though the
tire may be approved for a higher load or inflation. Some rims and wheels are stamped with a
maximum load and maximum cold inflation rating. If they are not stamped, consult the rim or
wheel manufacturer for the correct tire inflation
pressure for the vehicle load. If the load exceeds the maximum rim or wheel capacity, the
load must be adjusted or reduced.
For further information on rims and tires (other than
Michelin), and for inflation and load limits, see the
"Tire and Rim Association Yearbook." Contact the
Michelin Tire Corporation for further data on their
tires.
Wheel Fastener Torque Values
For torque values for disc wheel fasteners, see
Table 1.
For torque values for spoke wheel rim clamp nuts,
see Table 2.
Disc Wheel Fastener Torque
Description
Nut Size
Wheel Manufacturer
Torque (dry threads):
lbf·ft (N·m)
8-Hole Disc Wheel With Two-Piece Flange Nuts
Front and Rear Wheel Nut
M22 x 1.5
All
450–500 (610–678)*
10-Hole Disc Wheel With Two-Piece Flange Nuts
Front and Rear Wheel Nut
M22 x 1.5
All
450–500 (610–678)*
10-Hole Disc Wheel With Inner and Outer Nuts
Front Wheel Nut
Rear Wheel Inner Nut
1-1/8–16
3/4–16
Alcoa
400–500 (540–678)†
Budd
450–500 (610–678)‡
Firestone and Motor Wheel
450–500 (610–678)
Alcoa
400–500 (540–678)†
Budd, Firestone, and Motor
Wheel
450–500 (610–678)
Alcoa
400–500 (540–678)†
Rear Wheel Outer Nut
1-1/8–16
Budd, Firestone, and Motor
Wheel
450–500 (610–678)
Wheel Stud Retainer Nut
3/4–16
All
175–200 (235–270)
* Torque values are given for lubricated threads.
† Torque values given are for dry threads. Lubricated threads should be tightened 300 to 375 lbf·ft (405 to 510 N·m). Lubricate threads with a mixture of 25 per-
cent colloidal graphite in cup grease or equivalent. Do not apply thread lubricant to ball seats of the nuts and wheels. Wipe it off if it is applied accidentally.
‡ On 1–1/8-16 wheel studs with a head (Fig. 1), tighten the wheel nuts 650 to 750 lbf·ft (990 to 1020 N·m).
Table 1, Disc Wheel Fastener Torque
Heavy-Duty Trucks Service Manual, Supplement 34, January 2007
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Wheels and Tires
Specifications
Spoke Wheel Rim Clamp Nut Torque
Description
Nut Size
5/8–11
Front Wheel Nut, 5 and 6 Spoke
3/4–10
5/8–11
Rear Wheel Nut, 5 and 6 Spoke
3/4–10
Manufacturer
Dry Threads: lbf·ft (N·m)
Dayton and Gunite
160–175 (215–235)
Webb
150–175 (205–235)
Dayton
240–260 (325–355)
Gunite
200–225 (270–305)*
Webb
200–250 (270–340)
Dayton and Gunite
160–175 (215–235)
Webb
150–175 (205–235)
Dayton
190–210 (260–285)†
Gunite
200–225 (270–305)
Webb
200–250 (270–340)
* On front axles with over 12,000 lb (5448 kg) capacity, tighten nuts 240 to 265 lbf·ft (325 to 360 N·m). Gunite part number W-854 nut, with a phosphate and oil
coating, must be used.
† When using channel spacers (see Fig. 2), recommended torque for rim clamp nuts is 190 to 210 lbf·ft (260 to 285 N·m); when using corrugated or
corrugated-channel spacers (see Fig. 3), permitted torque is 240 to 260 lbf·ft (325 to 355 N·m).
Table 2, Spoke Wheel Rim Clamp Nut Torque
1
2
01/21/93
1. Head-Type Wheel Stud (1-1/8–16)
f230015a
2. Wheel Nut
Fig. 1, Head-Type Wheel Stud
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Heavy-Duty Trucks Service Manual, Supplement 34, January 2007
40.00
Wheels and Tires
Specifications
f400033a
05/16/94
Fig. 2, Channel Spacer
1
2
05/30/2006
f400031a
1. Corrugated Spacer
2. Corrugated-Channel Spacer
Fig. 3, Corrugated Spacers
Heavy-Duty Trucks Service Manual, Supplement 34, January 2007
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