
Alignment & Adjustments
28
17730-241
AR2
™
40K • 46K
6 . Deflate the suspension by using one of the following methods, if the vehicle:
■
Method 1 —
is equipped with a suspension dump system in the cab, deflate the suspen-
sion air system by using the cab dump valve control
■
Method 2 —
is not equipped with a suspension dump system, detach both the upper rub-
ber grommets of the height control valve linkages from the height control valve arms and
exhaust the suspension system air by lowering the height control valve arms, see Figure 7-1
7 . Inflate the suspension by using one of the following methods, if the vehicle:
■
Method 1 —
is equipped with a suspension dump system in the cab, inflate the suspension
air system by using the cab dump valve control . Allow the suspension system to inflate
■
Method 2 —
is not equipped with a suspension dump system, raise the height control
valve arms and attach the upper rubber grommets of the height control valve linkage to
the height control valve arms . Allow the suspension system to inflate
8 . Locate the wheel end where the height control valve is installed .
9 . Measure the actual suspension ride height, (Dimension
A
) the distance from the bottom of
the frame rail to the axle centerline, see Figure 7-2 .
10 . Measure the referenced ride height (Dimension
B
) from the top of the of the trailing arm
saddle to the centerline of the center bushing, see Figure 7-2 .
NOTE
A vehicle equipped with dual height control valves must measure the ride height at each height
control valve location .
TABLE 7‑1
11 . Compare the actual (Dimension
A
) ride height to
the (Dimension
B
) for your suspension in Table
7-1 .
12 . If the ride height is
correct
, no further adjust-
ment is necessary . If
incorrect
, then height control valve adjustment is required . Refer to the
Adjustment Procedure in this section .
FIguRE 7‑2
AdjuSTMENT pROCEduRE
SERVICE HINT
When inspecting or setting the ride height on a vehicle, it is recommended to have a load on the
vehicle . Loading the vehicle to its normal operating condition increases ride height setting accuracy .
1 . Drive the vehicle onto a level surface .
2 . Relax the suspension by slowly moving the vehicle back and forth several times in a straight
line without using the brakes . This will slacken or loosen the suspension as the vehicle is posi-
tioned . End with all wheels positioned straight ahead . Roll to a stop without the brakes being
applied .
dO NOT
set the parking brake .
3 . Chock front wheels of the vehicle .
dIMENSION
A
dIMENSION
B
9½" (241 mm)
4
15
⁄
16
" (125 .4 mm)
10½" (267 mm)
5
23
⁄
32
" (145 .4 mm)