Before performing axle alignment or upper torque rod
adjustment, remove road debris from suspension and
perform the preliminary procedures listed below.
Park vehicle on a level floor.
Release parking brake.
Check rear wheels for runout and correct if
Move vehicle forward and rearward several
times to relieve internal stress.
Turn wheels in a straight ahead position.
The following alignment check (measuring of the
suspension) applies to all tandem suspensions covered
in this manual, all 4 X 2 vehicles having spring
suspension with torque rods, and IH air suspensions with
tapered leaf springs. In the event axle adjustment is
necessary, refer to the AXLE ADJUSTMENT portion of
this section and the appropriate procedure for the
suspension being serviced.
Clamp a straightedge to top frame rail ahead of
forward rear axle on 6 x 4 vehicles and ahead of rear
axles on 4 x 2 vehicles. Use a framing square
against straightedge and outside surface of the
frame side member to insure straightedge is
perpendicular to frame, as in Figure 1.
Figure 1 - Straightedge Location on Frame
Suspend a plumb bob from the straightedge in front
of the tire and on outboard side of the forward rear
axle on 6 x 4 vehicles or rear axle on 4 x 2 vehicles.
(See Figure 2.)
Position a slotted bar such that pointers are engaged
in center hole of (both) rear axles(s).
Figure 2 - Plumb Bob Locations
Measure distance between cord of plum bob and
pointer on forward rear axle of 6 x 4 vehicles or rear
axle on 4 x 2 vehicles. Record dimension "A" as in
Figure 3 - Measure Dimension "A"
Position slotted bar with pointers on opposite side of
vehicle in same manner and measure corresponding
distance as in Step 4. Record this dimension.
Any difference in dimensions from side to side in
excess of 3.175 mm (.125 inches) must be
Refer to the AXLE ADJUSTMENT portion of this
section for procedures to equalize difference in
dimensions which exceed 3.175 mm (.125 inches).
CTS-4016W - Page 2