Regional Haul Model Operator's Manual - Peterbilt Motors Company

REAR AXLE AND SUSPENSION
It is important that U–bolts remain tight. Severe use of
your vehicle can cause them to loosen faster. But all vehicles
need to have their U–bolts checked and tightened
regularly. Be sure someone with the proper training and
the right tools checks and tightens the U–bolts on your
Regional Haul vehicle.
New springs “settle-in” after the vehicle's initial service,
causing the U–bolts to become loose. After the first 500
miles (800 km) of operation, inspect the suspension periodically,
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.
Rear Axle Lubrication
PREVENTIVE MAINTENANCE
Check oil level with the vehicle parked on level ground
and the fluid warm. The level should be even with the bottom
of the filler hole.
CAUTION: Do not mix lubricants of different
grades; although, mixing different brands of
the same grade lubricant (meeting MIL–L–
2105–C), is acceptable. Lubricants of different
grades are not compatible and could damage
the axle.
NOTE: In all cases, the lubricant supplier
assumes full responsibility for the performance of
their product, and for product and patent liability.
Initial Change: Change lubricant in new or rebuilt axle
assemblies within the first 3,000 to 5,000 miles (4800 to
8000 km). For recommended types and brands of lubricants,
contact your Peterbilt Dealer or Authorized Service
Center. See the Maintenance Manual and the axle manufacturer's
Service Manual for further information on servicing
drive axles.
– 246 – Y53-6033 Regional Haul (R05/10)