An axle spring is a device used to cushion the ride of a vehicle or trailer. Often consisting of a leaf or a coil-type spring, the axle spring is mounted between the axle and the chassis or frame of the vehicle the unit is attached to. With a coil-type axle spring, there is rarely a problem that requires attention; however, with a leaf spring, there are several types of damage that can require attention to correct. Broken leaves, broken spring pack bolts and worn shackle bushings are some of the frequently occurring problems that can plague a spring.
Nearly all vehicles and trailers use some type of axle spring to ensure a smooth ride while traveling on nearly any surface. Coupled with a shock absorber, the axle spring allows the vehicle to seemingly float over imperfections in the road's surface. This is due, in part, to the spring taking the brunt of the force from any bump encountered. As the spring compresses in response to contacting a bump or hole in the road, the tire remains in contact with the road instead of bouncing up and off of the road. This allows the operator to maintain control of the vehicle as the suspension absorbs the impact and deflects it accordingly.
Without a spring, the entire vehicle would bounce off of the road when a bump or hole was encountered. This would make for an ill-handling vehicle at best, and a potential accident could occur from the erratic movement of the vehicle. By placing a spring on the axle, the tires are spared when large road hazards are encountered. With no axle spring, the tire would be forced to absorb the brunt of the impact with the hazard and could blow out due to the force of the impact. Broken leaf-type springs are often detected by a telltale cracking or bumping noise emitted from the spring when a large bump is struck.
To fix a broken leaf spring, the spring must be removed from the axle and the vehicle. Once removed, the center bolt must be removed from the spring pack and the springs separated. Once separated, the broken spring must be replaced with a new spring. After being replaced, the axle spring pack must be bolted back together. This is best accomplished by clamping the axle spring in a vice and compressing the axle spring pack until the bolt can be slid through the leaves and the retaining nut can be tightened on the bolt.