operators_manual

WARNING
Failure to maintain the specified torque
values
or to replace worn parts can
cause component system failure, pos-
sibly resulting in an accident. Improp-
erly tightened (loose) suspension U-
bolts can lead to unsafe vehicle condi-
tions, including: hard steering, axle
misalignment, spring breakage or ab-
normal tire wear. Failure to comply
may result in death, personal injury,
equipment or property damage.
CAUTION
DO NOT spray the suspension with
chemical
products or mineral oil; it can
cause damage to the bushings.
NOTE
Failure to follow these recommenda-
tions could void warranty
.
Visual Inspection
For all vehicles, mandatory maintenance
procedures include retightening of U-bolts
and complete inspection. Even with proper
maintenance, however
, many factors affect
the service life of springs and suspension
components: fatigue, vehicle gross weight,
type of load, road conditions, and vehicle
speed. All vehicles need to have their U-
bolts checked and tightened regularly, but
severe use of your vehicle can cause them
to loosen faster. It is important that U-bolts
remain tight. Be sure someone with proper
training and the right tools checks and
tightens the U-bolts on your vehicle. After
the first 500 miles (800 km) of operation,
periodically inspect the suspension as
noted below:
• Visually check for loose or missing
fasteners, cracks in hanger, or axle
connection brackets
• Check that springs are centered in
hangers and in good condition
• Check for cracks, wear marks,
splits, or other defects on the
surface of the spring
• Replace defective parts. Because
repaired springs cannot be fully
restored to their original service
life, replace the complete assembly
if cracks or other defects are
detected
•
After replacement of any part or
discovery of loose components,
check the torque of all fasteners
• New springs settle-in after the
vehicle's initial service, causing the
U-bolts to become loose
Rear Suspension Fasteners
To maintain the performance of the air
suspension, check fastener torque values
after the first 2,000 miles (3,200 km) of
service and every 60,000 miles (96,000
km) thereafter. Torque recommendations
apply to fasteners supplied and installed by
vehicle manufacture. The values listed at
the back of this chapter (See Suspension
U-Bolts, Grade 8 on page 251 and Frame
Fastener Torque Requirements on page
250), are for cadmium plated or phosphate
and oil fasteners only.
Rear Suspension U-Bolts
U-bolts are difficult to tighten unless you
have the right equipment. If you cannot
tighten them correctly yourself, be sure to
have them checked and tightened regularly
by an authorized mechanic.
MAINTENANCE - Rear Axle and Suspension
232 Y53-6096-1C1 (09/20)
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