How to Adjust and Align Rear Leaf Springs
Rear leaf springs are one of the components that make up the suspension system of a vehicle. They enhance on and off road performance, handling and control. Failure to take care of such components can jeopardize the safety of the vehicle and its occupants. After aligning leaf springs make sure that the car is safe and controllable. This however should not be done on public or busy roads.
Step 1 – Jack up the Car
Park the car in a spacious and flat surface; make sure there is enough space to work at the car’s rear. Carefully jack the car up and place it on stand. It is advisable to put the car in neutral with the parking brake off.
Step 2 – Remove and Inspect Leaf Spring
Position one jack stand 3 to 4 inches from the end of the leaf spring, take care not to lift the car too high. Use a wrench to loosen the bolts and remove the rear spring bolt from the trailing arm and spring. Carefully lower the jack to ease the pressure on the spring. Remove the four rear spring center plate bolts using a wrench. Remove the springs and place on a clean surface.
Check the condition of the leaf springs; watch out for damage, wear and tear. If they are damaged, replace them with new ones.
Step 3 – Reinstall, Align and Adjust Leaf Spring
Reinstall leaf springs and make sure that the bolts are firm. Measure the height of the vehicle from the ground to the mid section of the car. Make sure the car is on a flat surface. Compare the results with the car’s service manual. Bounce the car up and down at the corners to stabilize the suspension before inspecting the vehicle’s height.
Measure the height of the vehicle at four points, the ground clearance of the; front wheel, adjustment cam bolt center at the front, rear wheel center, and rear leaf spring front side bushing center.
Step 4 – Adjust Toe In
Check if the toe-in is within the specified range as recommended by manufacturers. Ideally it should lie in the middle of the specified range. Remove the rack boot set clips. Use a wrench to loosen the tie rod end lock nuts. To adjust toe-in, carefully turn the right and left rack ends.
Insure that the lengths of the right and left rack ends are the same. Fasten the tie rod end lock nuts and take care not to use too much force. Replace the boots on the seats and reinstall the clips.
Step 6 – Inspect Wheel Turn Angle
Check that the right and left turning angles of the inside and outside wheels are within the specified ranges. To inspect wheel turn angle, check the right and left rack end lengths for all wheels and make sure they are within the range specified by the manufactures.
Finish alignment by inspecting the camber, caste and steering axis inclination. To re-adjust the camber and caster, loosen the nut and bolt using a wrench and turn the camber adjust cam and toe adjust cam and make adjustment. Ideally the camber and caster should be adjusted to their central values.
- It is advisable to align the vehicle while the car is empty.
- Make sure that the new alignment and adjustment are as specified in the car’s service manual.