freightliner M2 Plus Maintenance Manual page 78

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7. Inspect the stabilizer bar, if so equipped, for
irregular bushing wear or cracks in the brackets.
The stabilizer bar is optional on 10,000- and
15,000-pound AirLiner suspension systems.
8. Remove the safety stands and lower the rear of
the vehicle to the ground. Run the engine until
air pressure of at least 100 psi (689 kPa) is
maintained throughout the system.
9. Check that all air springs are inflated.
Freightliner AirLiner Control Rod
Check
1. Without disconnecting the control rods, use your
hand to attempt to move each of the control rod
ends up, down, in, and out. If there is any
movement, examine the control rods for wear or
damage. Replace if necessary.
2. Inspect the rubber bushings for cracks or cuts.
3. Check for any shifting of the barpin.
4. Check for cracks in the metal components and
welds.
NOTE: The Freightliner AirLiner Suspension is
manufactured at numerous weight ratings up to
46,000 pounds. The control rod on the 46,000-
pound-rated suspension is larger, and is
fastened differently than on other applications.
Freightliner TufTrac
1. Inspect the suspension spring assemblies for
pitted, cracked, broken, or abnormally bent
leaves, and extreme rust. If any of these
conditions exist, replace the spring assembly.
WARNING
Do not replace individual leaves of a damaged leaf
spring assembly; replace the complete spring
assembly. Visible damage (cracks or breaks) to
one leaf causes hidden damage to other leaves.
Replacement of only the visibly damaged part(s)
is no assurance that the spring is safe. On front
spring assemblies, if cracks or breaks exist in the
two top leaves, a loss of vehicle control could
occur. Failure to replace a damaged spring
assembly could cause an accident resulting in
property damage, serious personal injury, or
death.
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IMPORTANT: On multi-leaf suspensions, closely
inspect each component of the leaf spring
assemblies, including the brackets, U-bolts, and
related parts.
2. Inspect the brackets for cracks in the castings.
Inspect the V-rod tower welds for cracking or
other signs of damage. Also check for contact
between the frame rail and the upper axle clamp
brackets. If contact exists, check the V-rod
bushing for wear. Check the V-rod fastener
torques.
3. Inspect the rubber center bearing and spring tip
pads for excessive wear, including de-lamination
of the rubber-to-metal shim interface, and
distortion and degradation of rubber.
4. Inspect the V-rods and lower control rods for
wear and looseness.
4.1 Without disconnecting the control rods,
use your hand to attempt to move each of
the control rod ends up, down, in, and
out. If there is any movement, examine
the control rods for wear or damage.
Replace if necessary.
4.2 Inspect the rubber bushings for cracks or
cuts.
4.3 Check for any shifting of the barpin.
4.4 Check for cracks in the metal
components and welds.
5. Check all fasteners for looseness.
6. Inspect the shock absorbers for oil leaks and
worn rubber bushings. Replace the shock
absorbers and/or rubber bushings if wear or
damage is noted.
Hendrickson Suspension
Inspection
Inspect the suspension assembly for wear, cracks,
and damage to its components. Replace the
component(s) if any wear, cracks, or damage exists.
Check all fasteners for tightness.
Check for distorted or frayed rubber at the beam end
bushings. If the bushings are damaged, replace
them.
Check that the ends of the equalizer beam are not
lower in the beam hanger.
Business Class M2 Plus Maintenance Manual, 02/10/2023
Suspension