Section 16: SUSPENSION
PA1593
21
4. SUSPENSION HEIGHT ADJUSTMENT
The flow of pressurized air from the accessory
air tank to the air springs is controlled by three
height control valves. The two rear valves are
mounted to the subframe and connected to the
rear axles through an arm and link connection.
The front valve is mounted to the subframe and
connected to the front air tank support. These
connections allow the valves to apportion air
pressure in the springs to the vehicle load,
maintaining normal ride height.
Immediate response height control valves
increase or decrease the air pressure in the
suspension system as required. One height
control valve is located
at center of front sway
bar
, and regulates air to front suspension air
springs in order to maintain the vehicle at the
required height. Two are located at the drive
axle, one on each inner side of rear
wheelhousing.
The appropriate vehicle body height is obtained
by measuring the clearance of all the air springs
installed on the vehicle. The two front air springs
clearance should be 11 ± ¼“ (279 ± 6 mm).
Refer to figure 24 to identify the correct area to
take measurement. The rear air springs
clearance should be 11 ½ ± ¼" (292 ± 6 mm).
FIGURE 24: TYPICAL AIR SPRING CLEARANCE
16058
At this point, it should not be necessary to make
an adjustment under normal service conditions.
However, if an adjustment is required, change
the position of the overtravel lever in relation to
the overtravel control body. The lever should be
moved up to raise vehicle height, and down to
lower it. Check that main air pressure is at
normal operating pressure and raise the vehicle
to the specified height.
CAUTION
Always adjust on "fill cycle". If it is necessary
to lower vehicle height, release sufficient air to
be well below height, and adjust to height or
fill cycle.
FIGURE 25: FRONT HEIGHT CONTROL VALVE
16100
The normal ride height is obtained by adjusting
air spring clearance of both front and rear
suspension as follows:
Front air spring clearance
1. With the vehicle at normal operating air
pressure [100 - 125 psi (689 - 860 kPa)],
measure air spring clearance. This
clearance should be 11 ± ¼“ (279 ± 6 mm).
NOTE
The measurement should be taken from
underneath the upper air spring support on
subframe to top of the lower air spring support
on axle (refer to figure 24 for more details). If
adjustment is required, begin with the drive
axle.
2. Loosen the clamp on the height control
valve rubber coupling and bring it up or
down (Fig. 25).
NOTE
Allow suspension to stabilize before taking
reading.
Summary of Contents for X3-45 2016
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Page 16: ...Section 00 GENERAL INFORMATION PA1593 12 FIGURE 12 METRIC US STANDARD CONVERSION TABLE 00005...
Page 17: ...Section 00 GENERAL INFORMATION 13 PA1593 FIGURE 13 CONVERSION CHART 00006...
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Page 72: ...Section 04 EXHAUST AND AFTERTREATMENT SYSTEM PA1593 14 7 TORQUE SPECIFICATIONS...
Page 73: ...SECTION 04 EXHAUST AND AFTERTREATMENT SYSTEM PA1593 15...
Page 74: ...Section 04 EXHAUST AND AFTERTREATMENT SYSTEM PA1593 16...
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Page 176: ...SECTION 06B ELECTRICAL 38 overcurrent working Circuit 306 shorted to ground...
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Page 205: ...Section 09 PROPELLER SHAFT PA1593 3 FIGURE 1 PROPELLER SHAFT ASSEMBLY 09002...
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Page 295: ...SECTION 16 SUSPENSION PA1593 9 2 5 TORQUE SPECIFICATIONS...
Page 296: ...Section 16 SUSPENSION PA1593 10...
Page 297: ...Section 16 SUSPENSION PA1593 11...
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Page 413: ...Section 22 HEATING AND AIR CONDITIONING PA1593 15 FIGURE 18 REFRIGERANT CIRCUIT CENTRAL SYSTEM...
Page 433: ...Section 22 HEATING AND AIR CONDITIONING PA1593 35 FIGURE 36 CENTRAL HEATING SYSTEM COMPONENTS...