AXLE ALIGNMENT Improper axle alignment will cause dog-tracking and excessive Ɵre wear. To check alignment of axles to king pin, use the following procedure: 1. Set empty trailer on level smooth surface, disconnect trailer brakes and bleed air tank. 2. Rock trailer back and forth for a distance of approximately 10 feet to relieve any binding in brakes or suspension bushings. 3. Tow trailer straight forward for a distance of approximately 30 feet. Stop trailer with tractor gears or tractor brakes only. 4. Disconnect tractor from trailer and ensure suspension ride height is properly adjusted. 5. Adjust landing legs to level trailer and set upper coupler to the correct ride height. 6. Do not remove wheels, but remove all hub caps and install axle center extensions. Use suitable kingpin jack or center extension to insure a clear path from the kingpin centerline to the axle center extensions. 7. Measure from kingpin extensions to both front axle center extensions. This distance should be the same on both sides (A = B) as shown in graphic below.
8. If not, remove and install new pivot bolts leaving them loose enough to adjust axle to square with the kingpin. Make sure there are no obstacles in front of wheels during alignment. 9. Measure from front axle center extensions to rear axle center extensions. This distance should be the same of both sides (C = D). If not, remove and install new pivot bolts leaving them loose enough to adjust rear axle to parallel with front axle. The suspension should now be in proper alignment with the kingpin.
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