How to Square a Trailer Axle

by C.L. Rease

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Trailer axles sitting out-of-square can cause a trailer to travel at an angle when towed. The travel angle increases the wear rate of the tires attached to the axles, or worse, causes you to lose control of the travel while driving. Both situations lead to potentially dangerous problems for you and the passengers in the tow vehicle. Adjusting the axle corrects the problem and eliminates dangers associated with out-of-square axles.

Step 1

Lower the front trailer jack to its lowest position. Place one jack stand on the back of each corner of the trailer. Raise the trailer jack to its highest position to lift the trailer's tires off the ground.

Step 2

Turn the hex nuts on the top of each U-bolt axle hanger four turns counterclockwise with a socket and 3/8-inch ratchet handle. Push on the axle. Loosen the hex nuts if the axle does not move.

Step 3

Pull a tape measure from the lower right-hand side of the bumper to the center of the axle's left side. Read the tape measure. Move the end of the tape measure to the lower left-hand side of the trailer's bumper. Measure the distance from the bumper to the center on the axle's right side.

Step 4

Add the two measurements. Divide this measurement by two. For example, one measurement of 164-1/2 and a second measurement of 164 add up to 328-1/2. Divide the sum by two for a measurement of 164-1/4.

Step 5

Pull the tape measure from the right-hand corner of the trailer to the center of the axle. Adjust the axle to the measurement determined earlier. Tighten the hex nuts of the U-bolt hangers. Move to the other side of the trailer. Set the other side of the axle to the predetermined measurement. Tighten the U-bolts on the left-hand side of the axle.