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Trailer Maintenance Procedures
THE IMPORTANCE OF FREQUENT INSPECTION AND PREVEN· TATIVE MAINTENANCE
FOR ANY MACHINE CANNOT BE OVER EMPHASIZED: YOUR
PRATT
TRAILER IS NO
EXCEPTION. PROPER CARE GREATLY REDUCES THE REPAIR COST AND THE AMOUNT
OF DOWNTIME.
Kingpin and Fifth Wheel Area
Inspect the kingpin for excessive wear, rough edges, looseness, broken or chipped out areas and cracks. Any
kingpin showing such condition must be replaced at once. Do not, under any circumstance, weld the kingpin
to compensate for wear. Once a kingpin has been heated its physical characteristics are changed and its
subsequent performance cannot be predicted.
Check and inspect the fifth wheel area for cracks, breaks, and for secure attachment to the trailer. Any
welding performed in this area is to be restricted to those welds specified by PRATT and is to be performed in
the manner prescribed by PRATT.
We suggest all repairs on the kingpin area be performed only by an authorized location referred by PRATT.
Rear Impact Guards
Your new PRATT Trailer has been designed & tested to meet the requirements of N.H.T.S.A. article 571.223
and 571.224.
The rear bumper should be checked during regular maintenance for cracks, bonds & etc. If repair is needed
please refer to T.M.C. Recommended Practice 732(T).
Wheel and Rim Care
Standard wheels on your PRATT trailer are cast spoke or steel disc wheels. Wheel nuts are inspected and
tightened to specifications at the factory and are checked again at pre-delivery. To maintain the correct torque
on the wheels of a new trailer the nut torque must be checked periodically. During normal highway operation
of a new trailer, this check should be made at the first 100,500, and 1,000 miles and every 5,000 miles
thereafter. Severe service conditions may require more tightening. Loose wheel nuts may cause shimmy,
uneven tire wear, and vibration. Elongated stud holes in the wheels may result from loose hub nuts. Wheel and
hub nuts must be torqued to proper specifications to provide maximum service life.
Spoke wheel installation and maintenance
RIM MOUNTING INSTRUCTIONS:
Rims must be correctly assembled, rim clamps must match the rim spacer width and rim clamp nuts must be
correctly tightened to assure maximum service life and maximum safety.
1. All parts must be clean, free of rust, dirt and paint..
2. Slide the inside rim over the wheel so the 28° mounting surfaces mate. Be sure the valve stem is pointing
out and is centered between two spokes.
3. Slide the rim spacer over the wheel and against the inner rim.
4. Slide the outer rim over the wheel. Be sure the valve system is pointing in and is centered between the
same spokes as the inner valve stem.
5. Install the rim clamps and nuts. Lightly tighten the rim nuts while rotating the wheel.
6. Tighten the rim nuts a quarter turn at a time in order shown until tightened to the correct torque.
Recommended Torque Dry: 200 to 250 Ft. Lbs.
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