Rear Suspension Removal and Replace on A and G body Pontiac’s 60’s -70’s

 

In this blog we will cover the removal and replacement of the rear control arms, shocks and swaybar on GTO’s and Grand Prix’s. This can be done without taking the rear end out of the car if you do one piece at a time. Start with spraying all nuts to be removed with your favorite rust remover. Put car on jack stands and remove rear tires.

Replacement of Upper Control Arms

The upper control arms are secured by two bolts each. Loosen nuts on each end. Have new arm, bolts and nuts ready for install. Make note of direction of the bolt as it will have to be installed in the same direction.

After removal of one side some movement on the axle will occur. If you are installing control arms with polyurethane bushings now is the time to put the supplied lubricant. Some alignment will be necessary to reinstall both bolts. Tighten the nuts to sucure the control arm. After both arms have been replaced tighten to the specified torque.

Replacement of Lower Control Arms

arms
Lower control arms from a Pontiac A body Upper is stock Lower is an aftermarket replacement

Much like the upper control arms the lowers are held by two bolts with nuts. The big difference is that the lowers have a sway bar on some models and the bolts are inside the frame. The bolts are most impossible if frozen to the control arm and will take some effort to get out.

Sway bar must be removed before you can remove the lower control arms. The sway bar is held on by two thru bolts on each side held on by two locking nuts.

Replace one control arm at a time and you can do it on the jack stands. This will allow you align with a little movement with a pry bar or clamp. Tighten up nuts to secure the control arm and torque to specifications after both new arms are in place.

Replacement of the sway bar is easy, just make sure the bar bend around the differential cover and the two bolts on each side are tourqued after everything is tightened and checked for alignment.

Replacement of the Shocks

Removing of the shocks will take some long extentions as the top two nuts on each side are very high. If you are going to replace the rear springs, do so while the shocks are removed. The bottom has a thru bolt that will be easy to remove.

Replacement of rear springs

Rear springs will be replaced when the shocks have been removed.  If you car is on jack stands you may have to lift the body to release the tension on the springs.  They will just slide out as they do not have any thing holding them in but the weight of the car and the limit of movement by the shocks.  Check the alignment of the top bushing to be replaced before the spring in put back.  Also make note of the position of the end of the spring on top, it will change the spring tension if not put in at the correct clock position.

Removal of bolts helpful hints

bolt lower control arm
Front lower control arm bolt inside frame

Use your favorite lubricant to help loosen the nuts. Some times heat will help if nut is stubborn, be careful not to set the fuel tank on fire as it is very close and in the way sometimes. If the front bolt will not budge you may have to drill off the head and drive toward middle of car. This is the only way as the other side does not have any room to pry or swing a weight to move the bolt out.

 

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