Setting and Replacing Trailer Axles

Trailer Axles: An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle is supported. In the latter case, a bearing or bushing sits inside the hole in the wheel to allow the wheel or gear to rotate around the axle.

Setting a Trailer Axle Guidelines

1.) Jack up your trailer frame. Support all four corners on jack stands or blocks.

2.) Locate the front and rear shackle hangers along either side of the trailer frame. Fasten one end of each leaf spring to a front shackle hanger with a bolt and socket wrench. Allow the leaf springs to hang down.

3.) Place the axle across the centers of the leaf springs. Raising one leaf spring at a time, attach the free end of each leaf spring to a rear shackle hanger on the trailer with bolts and a socket wrench. The axle should be suspended in the air across the leaf springs.

4.) Secure both ends of the axle to the center of each leaf spring with a U-bolt, retainer bracket and socket wrench.

5.) Tighten all the bolts to the manufacturer’s torque specifications with a torque wrench. Remove the jack stands or blocks and lower the trailer.

6.) Check the axle’s alignment by comparing the distances from the center of either wheel to the tip of the trailer tongue. The distances should be within 1/8 inch of one another.

Replacing the Trailer Axle Guidelines

1.) Raise the trailer up in the air using the jack and secure it on jack stands. Double check that the trailer is solidly on the stands prior to crawling underneath it. Remove all of the tires using the tire iron.

2.) Disconnect the brake lines running to the brakes, if your trailer is so equipped, using a line wrench. Then unbolt the axle from the leaf springs at the u-bolts using the 1/2-inch ratchet and socket set. If the trailer has shocks, disconnect those at this time using the ratchet.

3.) Place your assistant on one side of the axle, with you on the other, and lift the axle over toward one side to get the axle free of the leaf spring. Repeat the process on the other side until the axle is completely free of the trailer, then slide it out from under the trailer.

4.) Slide the replacement axle under the trailer with the help of your assistant and position it on the leaf springs by reversing the procedure in Step 3. Secure the new axle to the leaf springs using the 1/2-inch ratchet and socket, as well as the shocks if equipped. Reinstall any brake lines using the line wrench.

5.) Reinstall the tires on the new axle using the tire iron, then lower the trailer off of the jack stands using the jack.