With the trailer empty, raise the axle(s) off the surface by relieving the air pressure on the lift axles.
^ WARNING
Collision Hazard. An empty trailer with the lift axle(s) in the down position can be unstable while towing, which can result in loss of control. Raise the lift axle(s) off the surface on an empty trailer before towing.
4.2 WHEELS AND TIRES Uneven tread wear can be caused by tire imbalance, axle misalignment or improper inflation. If you observe uneven tread wear, take the trailer to an authorized truck/trailer service center for diagnosis. Trailer wheels and lugs are subjected to high side loads. This can cause the wheel lugs to become loose. Check to be certain wheel lugs are tightened to 450-500 lb ft of torque. Refer to the maintenance section for the proper tightening procedure. Failure to perform this check may result in a wheel parting from the trailer, and a crash leading to death or serious injury. You must use a torque wrench to obtain the proper tightening of the lug nuts. 4.3 ALIGNMENT Properly aligned trailer axles optimize fuel economy and driveability, and help prevent excessive tire wear. A perfect alignment scenario has all trailer wheels parallel to one another and perpendicular to the centerline of the trailer. However due to uncontrollable factors, this perfect scenario is often an unreasonable expectation. A more likely alignment scenario has the trailer wheels parallel within a very small tolerance range to one another and perpendicular within a very small tolerance range to the centerline of the trailer. There are two important trailer axle angles that must be kept within recommended tolerance ranges: thrust angle and scrub angle. These angles, when out of tolerance, can lead to increased rolling resistance, excessive tire wear and can contribute to trailer “dog tracking.” Dog tracking is a condition where the trailer does not follow or track directly behind the truck as the vehicle is being operated in a straight line and is influenced by body rail alignment, king pin location, axle side-to-side location, and other things. If realignment is necessary, take the trailer to your dealer or an authorized trailer service center.
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