Regional Haul Model Operator's Manual - Peterbilt Motors Company

PREVENTIVE MAINTENANCE
REAR AXLE AND SUSPENSION
WARNING! Do not operate the vehicle if the
U–bolts are not properly tightened. Loose U–
bolts do not properly secure the axle to the
suspension. This could cause loss of vehicle
control and an accident resulting in death or
injury. Loose U–bolts can also cause uneven
tire wear and poor alignment.
Suspension alignment should be checked when any one
of the following conditions exist:
• Discovery of loose suspension fasteners (Any
torque below the recommended torque value.).
• Discovery of elongated holes in a suspension component.
• Bushing replacement.
• Excessive or abnormal tire wear.
NOTE: To ensure an accurate torque reading,
use properly maintained and calibrated torque
wrenches.
Grade 5 Capscrew Torque Specifications
Capscrew Body
Torque
Size
(inches-thread)
Lb. ft. N.m.
1/4-20 6—9 8—12
-28 7—10 9.5—14
Grade 5 Capscrew Torque Specifications
5/16-18 13—18 18—24
-24 14—20 19—27
3/8-16 22—32 30—43
-24 25—40 34—54
7/16-14 35—50 47—68
-20 39—56 53—76
1/2-13 54—77 73—104
-20 58—87 79—118
9/16-12 78—111 105—151
-18 87—124 118—168
5/8-11 108—154 147—209
-18 122—174 166—236
3/4-10 192—273 260—370
-16 214—305 290—414
7/8-9 309—441 419—598
-14 341—486 462—659
1 -8 464—662 629—898
1-12 508—724 689—982
Grade 8 Capscrew Torque Specifications
Capscrew Body
Torque
Size
(inches-thread)
Lb. ft. N.m.
1/4-20 9—12 12—16
-28 10—14 14—19
Regional Haul (R05/10) Y53-6033 – 249 –