
251-Trailer-ISM 09-13-18 Page 11 ENG
Pivot Bushing Replacement Procedure
Bushings should be replaced in the two (2) pivot con-
nections at the same time (Figure 6).
1. Remove wheels and tires. Support lower beam/
pivot assembly.
2. Remove the shock absorber. Disconnect limiter
chain. Disconnect air spring from frame.
3. Disassemble pivot connections. Discard pivot
hardware. Inspect at washers and alignment
washers. Replace, if necessary.
4. Remove lower beam assembly (LBA)/Pivot As-
sembly from hangers.
5. Remove two pivot bushings and discard.
6. Inspect end cap and washers on pivot assembly
for damage/wear.
7. Check pivot assembly for excessive play by mov-
ing assembly back and forth. Remove from LBA
for further inspection and replacement, if neces-
sary (Figure 6).
8. Clean any foreign debris and corrosion out of the
pivot connection eyes with a wire brush.
9. Liberally apply P80®lubricant to the inside of the
eyes and outside of replacement bushings.
10. Press bushings into the pivot connections. Check
that bushings are centered within each eye.
11. Aach LBA/Pivot Assembly to hangers. Install
pivot hardware and washers. NOTE: Do not ap-
ply nal torque.
12. After aligning axle to SAE or TMC recom-
mended standards, torque pivot bolts to 500 ft-lb
(675 N-m).
NOTE: Set the suspension to specied mounting
height before torquing pivot bolt to prevent pre-
loading the rubber in the bushing.
13. Reassemble suspension. Torque to spec (Page 7).
14. Connect height control valve linkage (if disco-
nected). Inate air springs.
15. Install wheels and tires.
16. Raise vehicle and remove support stands. Lower
vehicle to ground.
LBA-Bearing Replacement Procedure
1. Remove wheels and tires. Support lower beam/
pivot assembly.
Pivot Bushing and Lower Beam Assembly (LBA) Bearing Replacement
Chock wheels. Raise vehicle to height that removes load from suspension and support with jack stands. Dis-
connect the linkage from the height control valve(s), if necessary, and exhaust all air from the air springs.
Failure to properly chock wheels, exhaust the air system and raise and safely support the vehicle
could allow vehicle/suspension movement that could result in serious injury.
2. Remove the shock absorber. Disconnect Limiter
Chain. Disconnect air spring from frame.
3. Disassemble pivot connections on pivot assem-
bly. Inspect and replace components as necessary.
4. Remove lower beam assembly (LBA)/
Pivot Assembly from hangers.
5. Grind/Cut weld around anti-turn washer. Re-
move LBA bolt, end-cap and dowel pin. Inspect
and replace components as necessary (dowel pin
must be retained for re-assembly).
6. Separate LBA from pivot assembly.
7. Remove bearing and thrust washer from lower
beam assembly and discard. Remove End-Cap
shim(s); thrust washer and composite bearing
from pivot assembly and discard.
8. Inspect LBA for excessive wear (Outside Diam-
eter of roll joint should be 4.438-inches ± 0.003”).
9. Press new composite bearing into both sides of
pivot assembly. Bearings should meet in the cen-
ter of the pivot assembly
10. Install thrust washer onto roll joint of lower beam
assembly. Insert LBA into the pivot assembly.
11. Check pivot assembly gap by installing thrust
washer, end-cap and bolt onto end of LBA roll
joint and tightening. Shim(s) will not be needed if
gap is less than 0.040” between roll joint end and
outside of pivot assembly.
12. Complete assembly by installing shim (if need-
ed), thrust washer, end-cap and bolt onto end of
LBA roll joint. Torque the lower beam assembly
bolt to 750 ft-lb (1017 N-m).
13. Insert dowel pin into end-cap. Weld anti-turn
washer to end cap as shown on engineering
drawing.
14. Install pivot assembly to hangers with pivot
hardware. Torque pivot bolt/nut hardware to
500 ft-lb (675 N-m).
15. Aach air spring, shock absorber, and limiter
chain. Torque to specications (Page 7).
16. Connect height control valve linkage and inate
air springs.
17. Install wheels and tires.
18. Raise vehicle and remove support stands. Lower
vehicle to ground.
Failure to torque suspension hardware can
result in suspension failure and void the warranty.