Changing a leaf spring shackle can be done in an afternoon with a few basic hand tools. The shackle supports the rear of the spring allowing it to pivot on the frame of your vehicle. Over time, the bushing can wear and the shackles can rust. Vehicles that see a lot of hard driving, such as off road trucks and race cars that use leaf springs, can actually break shackles or bolts. A damaged or broken shackle will allow the leaf spring and axle to move, adversely affecting your handling.
Place a floor jack under the rear differential of your vehicle and raise it off the ground. Position a set of jack stands under the frame to support the vehicle.
Lower the jack and allow the suspension to droop, taking the weight of the vehicle off the shackle. This will keep the shackle from binding and allow you to remove the mounting bolts.
Remove the lower mounting bolt from the shackle and spring using a socket and ratchet. Lower the axle so the spring drops out of the shackle.
Remove the upper mounting bolt that attaches the shackle to the mount on the frame. Pull the shackle off the frame. If it has been on there for a long time, you may need to use a dead blow hammer to encourage it to come loose.
Insert the new shackle onto the frame and insert the mounting bolt. Leave the bolt loose for now so you can move the shackle around to help align the shackle and spring.
Raise the rear axle with the jack and align the spring eye with the shackle. Slowly work the spring into the shackle, raising the jack a little at a time until the holes in the shackle and the spring eye line up.
Install the mounting bolt through the shackle and spring. Tighten the bolt with a ratchet and socket. Tighten the upper mounting bolt using a socket and ratchet.
Jack up the car and remove the jack stands. Slowly lower the car back down to the ground and double check the bolts, verifying that they are still tight with weight on them.
Use the jack to raise and lower the axle as you line up the spring eye with the shackle. It will save your back every time.