Replace a trailer axle by lifting the trailer, removing the wheels, disconnecting all mechanical parts connected to the axle, sliding the axle out and replacing it with the new axle. The process may vary depending on the size, type and features of the trailer. An axle can be replaced as part of a needed repair or with a stronger axle to increase its load capacity. At least two people are required to complete the axle change.
With the trailer parked on a level surface, jack it up, and secure it on jack stands. Use a lug wrench to remove both wheels. If the trailer is equipped with a braking system or shock absorbers, those need to be disconnected next using a line wrench and the appropriate size socket wrench respectively. Once everything is disconnected, unbolt the leaf springs.
Have your helper assist you in lifting one end of the axle and sliding it horizontally until it is clear of the leaf spring. Repeat the process for the other side, and remove the old axle. Slide the new axle in place in the opposite manner of the old part's removal. Securely fasten the axle to the leaf springs, reconnect any disconnected equipment, put the wheels back on, and lower the trailer to the ground.