Hendrickson PRIMAAX EX - U-Bolt Fastener Maintenance

PRIMAAX
®
EX / PRIMAAX
®
for Volvo Vehicles
17730-254 19 Preventive Maintenance
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Fasteners — Visually inspect for any loose or damaged fasteners on the entire suspension.
Make sure all fasteners are tightened to a torque value within the specified torque range. See
Torque Specification Section of this publication for recommended torque requirements. Use
a calibrated torque wrench to check torque in a tightening direction. As soon as the fastener
starts to move, record the torque and correct the torque if necessary.
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Frame hanger bracket — Visually inspect for any signs of loose fasteners, movement, or
damage. Verify the frame attaching fasteners have the proper torque values maintained.
See vehicle manufacturer for proper torque specifications.
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Height control valve and Air lines — Check the suspension air system for air leaks. Check
all air lines for proper routing. Check for chafing or pinched air lines. Check the height con-
trol valve linkage for damage or interference with peripheral components.
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QUIK-ALIGN connection — Visually inspect the connection for signs of looseness or move-
ment. Visually inspect the bushing for wear. Verify the connections have the proper torque
values maintained. See Torque Specification Section of this publication for recommended
torque requirements.
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Shock absorbers — Visually inspect for any signs of dents or leakage. Misting is not con-
sidered a leak, see Shock Absorber Inspection in this section.
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Tire wear — Visually inspect the tires for wear patterns that may indicate suspension dam-
age or misalignment.
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Top pad/Longitudinal torque rod connection — Visually inspect the connection for signs
of movement or damage. Use a lever check to help assess movement in this joint, see
Longitudinal and Transverse Torque Rods in this section for proper inspection. Verify the Top
Pad/Longitudinal Torque Rod connections have the proper torque values maintained. See
Torque Specifications Section of this publication for recommended torque requirements.
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Torque rods (longitudinal and transverse) — All torque rods must be inspected for loose-
ness, torn or shredded rubber, bushing walk-out, and for proper fastener torque. If there is
metal-to-metal contact in the bushing joint, this is a sign of excessive bushing wear and
the torque rod needs to be serviced, see Longitudinal Torque Rod inspection in this section.
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U-beam assembly — Visually inspect the overall condition of the support beam for dents,
dings, or other damage on the outer edges of the beam flanges. Visually inspect the D-pin
bushings for tearing or extreme bulging. Check for any metal-to-metal contact in the bushed
joints.
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Wear and damage — Visually inspect all parts of the suspension for wear and damage.
Look for bent or cracked parts.
See vehicle manufacturer’s applicable publications for other preventive maintenance
requirements.
U-BOLT FASTENERS
SERVICE HINT Due to certain pinion angle configurations, the removal of the D-pin bolts may be necessary to
access the U-bolt locknuts, see Figure 6-5.
1. U-bolt locknuts must be torqued to specification at pre-delivery.
2. U-bolt locknuts must be re-torqued at 1,000 miles.
3. Thereafter, follow the inspection and re-torque intervals below:
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Off-highway and severe service – Every 25,000 miles or 6 months, whichever comes first
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100% On-highway – Every 50,000 miles or 12 months, whichever comes first
NOTE Current Hendrickson Truck Suspension Systems U-bolt clamp group hardware for the
PRIMAAXEX / PRIMAAX suspensions are ¾"-16 UNF Grade C locknuts and ¾"-16 UNF Grade 8
U-bolts which are phosphate and oil coated.