TM 9-2330-271-14&P
(3) Jack up axle to proper design height from
NOTE
horizontal axle centerline to underside of frame (14
It will take 2 to 6 seconds after
inches plus or minus one-eighth of an inch). Tighten
adjustment of nylon block before air
nuts (25) with axle in proper height position to a torque of
starts to flow through valve. This is
150 lb-ft.
caused by the built-in time delay.
(4) Install cap screws (5), flat washers (27)
(7) Adjust valve by loosening adjustment lock
and nuts (28) and tighten to a torque of 200 lb-ft. (table
nut and carefully moving nylon block (fig. 4-41) until
dimension of 14 inches, plus or minus one-eighth of an
inch, is reached. Tighten adjustment lock nut.
Table 4-3. Torque Limits
(8) Disconnect linkage and let springs deflate
about half way. Reconnect linkage and allow springs to
Nut size
Torque limits
inflate. When valve shuts off, check height dimension
(lb-ft)
again.
Air Ride Suspension and Air
(9) Repeat steps (6), (7), and (8) above until
Mounted Kingpin
proper 14 inches, plus or minus one-eighth of an inch,
1/2-inch
25 lb-ft
dimension is reached.
5/8-inch
140 lb-ft
(10) Disconnect the valve adjusted in previous
3/4-inch
200 lb-ft
steps and move actuating arm to a vertical down position
3/4-inch (air spring only)
20 lb-ft
to deflate springs.
7/8-inch
300 lb-ft
(11) Repeat steps (5) through (10) above with
1-inch
450 lb-ft
the opposite height control valve.
1-1/8 inch
700 lb-ft
(12) Connect both actuating arms with their
1-1/4 inch
900 lb-ft
respective linkage. When springs are fully inflated and
Piston nut inside air spring
50 lb-ft
valves shut off, check height dimension. Both valves
should be synchronized.
(5) Reconnect linkage to height control valve.
(6) Install wheels and remove blocking and
4-57.
Replacement of Air Suspension System
jacking equipment.
Components
c. Replacement of Torsion Bar Only (fig. 51).
(1) Block up semitrailer to remove all weight
a. Removal of Rubber Bushing and Torsion Bar
from suspension.
(2) Remove front or rear wheels as
(1) Remove weight from suspension by
applicable.
blocking up semitrailer and jacking up axle. Remove
(3) Grind a one-fourth inch by 45 degree
front or rear wheels as applicable.
chamfer on one end of new torsion bar.
(2) Disconnect linkage from height control
(4) Remove outer nuts (28), flat washers (27),
valves and depress actuating arms to exhaust air
and cap screws (5). Loosen inner nuts (28).
pressure from air springs.
(5) Place chamfered end of new torsion bar
(3) Remove nuts (28), flat washers (27) and
against end of old torsion bar (32) and drive out old
cap screws (5) and loosen frame bracket nuts (25).
torsion bar. Make sure notch in new torsion bar is
Drive torsion bar (32) completely out of assembly using
positioned to receive cap screw in outer torsion bar
care not to mushroom bar end.
clamp of left hand equalizing arm (16).
(4) Carefully let both equalizing arms (16)
(6) Install cap screws (5), flat washers (27),
down away from frame brackets. Push out bushing (31).
and nuts (28); tighten all nuts to a torque of 150 lb-ft.
b. Installation of Rubber Bushing and Torsion Bar
(7) Install wheels and remove blocking and
jacking equipment.
(1) Slip in new bushing (31) and rotate, as
d. Removal of Air Spring (fig. 51).
near as possible, to operating position. Place spacers
(1) Block up semitrailer to remove all weight
(24) on ends of bushing and move equalizing arms (16)
from suspension.
back to their proper positions relative to frame brackets
(2) Disconnect linkage from height control
(29). Line up bushing square holes with arm square
valve supplying faulty air spring and exhaust pressurized
holes to receive torsion bar.
air by moving actuating arm down.
(2) Insert torsion bar (32) through arm ends
(3) Disconnect air line (8) from top of air
and bushings. Make sure that notch in bar is alined to
spring (15). Remove upper mounting nuts (11 and 12),
receive offset cap screw (5).
lock washers (10 and 13), and flat washer (9). Remove
lower mounting cap screws (17) and lock washers (13).
4-62
