A. MEASURING REAR SPRING HEIGHT
When measuring the rear spring heights, the vehicle should be placed on a level floor, have the correct front suspension height, the correct tire pressures, no passenger or luggage compartment load and a full tank of fuel.
(1) Jounce the vehicle several times (front bumper first). Release the bumpers at the same point in each cycle.
(2) Measure the shortest distance from the highest point on the underside of the rear axle bumper strap (at the rear of the bumper) to the top of the axle housing.
(3) Measure both the right and left sides.
If these measurements vary by more than 3/4 inch (from side to side), it is an indication that one of the rear springs may need replacing. It is normal for rear springs to show some reverse arch, even with no load, so appearance alone should not be the reason for spring replacement. Springs may "bottom" under abnormal loading conditions, particularly when road dips and railroad crossings are encountered at relatively high speeds.
B. REAR SPRINGS REMOVAL
(1) With the vehicle body frame supported on the floor stands and jack pressure under the axle housing, disconnect the shock absorbers front the studs on the spring plates.
(2) Lower the jack until it supports only the weight of the axle housing and remove the rear spring rear shackle.
(3) Loosen the rear spring pivot bolt nut. The nut should be backed off until it is retained on the pivot bolt by two or three threads.
(4) Using a pry bar between the pivot bolt nut and the body frame, force the pivot bolt outward until the nut contacts the spring mounting bracket.
(5) Remove the pivot bolt nut and using a suitable tool, force the pivot bolt out of the spring.
(6) Remove the spring "U" bolts and the spring.
C. REAR SPRING INSTALLATION
(1) Position the springs in their respective front hangers and install the pivot bolts and nuts (finger fight only).
(2) Install the spring shackles and nuts.
(3) Install the spring "U" bolts and nuts.
(4) Tighten the spring U-bolt nuts 50 foot-pounds torque and shackle bolt nuts 40 foot-pounds torque.
(5) Connect the shock absorbers.
(6) Remove the vehicle floor stands and with the vehicle weight on the wheels, tighten the front pivot bolt to 125 foot-pounds torque.
(7) The bushings and shackles should not be lubricated at any time. Measure the vehicle curb height whenever a rear spring or shackle has been replaced.