This article is one in a series that have been released in conjunction with Wayne's book, 101 Projects for Your Porsche 911. The book contains 240 pages of full color projects detailing everything from performance mods to changing your brake pads. With more than 650+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any Porsche 911 owner's collection. See The Official Book Website for more details.
As the 911s age, the tendency is to find them with worn out bushings, particularly the sway bar bushings. On the 1974 and later cars, the front and rear sway bars were mounted to the suspension and ran underneath the body of the car. Replacement of the rear bushings is a relatively simply process, but the replacement of the front ones requires a bit more effort.
The first step in replacing your bushings is to figure out if they need to be replaced. Carefully inspect them for cracking, and also check to make sure that their inner diameter hugs the sway bar tightly. If they do not appear to be worn, then simply apply a little bit of lithium grease inside the bushing. If they are worn, then they will need to be replaced.
Begin the process of replacing the front bushings by jacking up the car, and removing the lower belly pan that covers the steering rack (see Pelican Technical Article: Installing the Turbo Tie Rod Kit). The two rear brackets that hold the center front sway bar bushings (1974+)should come off when you remove the belly pan. Use the sheet metal seam of the car as a point for placing the jack stand: you will need full access to the a-arm and cross member.
Now, remove the bolts that anchor the front of the a-arm to the chassis. Refer to Project 64 for more details. Once you have the front of the a-arm disconnected, loosen and remove the torsion bar adjuster screw. Remove the adjuster lever as detailed in Project 64 as well. Now, loosen and remove the large bolt that holds the cross member to the chassis. Make sure that you are not using the cross member as a support with your jack stand. Removing the bolt in this condition may make the car unstable.
When this bolt is loose, you should be able to pull the a-arm out of the cross member. Let it hang from the ball joint underneath the shock. You should now have enough leeway to maneuver the a-arm so that you can slide the sway bar out of the bushing. Slide the other end of the sway bar out as well once you have one side clear.
The new replacement bushings are split down the middle, so they should easily slide onto the bar and into the bracket that is welded onto the a-arm. Remove the old bushings, and insert the new ones, making sure that you coat the bushings with some white lithium grease on the inside. Place the sway bar into the a-arm on one side, and then into the a-arm on the other side. Reattach the a-arm and torsion bar lever according to the directions in Pelican Technical Article: Replacing/Upgrading Torsion Bars. Bolt up the belly pan underneath the car, and you are done with the front bar.
On the early cars manufactured before 1974, the sway bar runs through the center of the car, not underneath. The replacement of the bushings simply involves the removal of the bar and droplinks. Remove the bar and install the new drop link bushings by pressing them in with a vise. The center bushings for the bar should be sandwiched between the mounting brackets for the sway bar and the inner fender wall. See Project 61 for some additional information on the early sway bars.
The rear bar is much simpler. Starting in 1978 cars, all six of the rear bushings are held in with bolts that can be easily removed. To replace the bushings, simply unbolt the brackets that hold them in. The small rear drop links are held in with bolts too, and can be removed simply by removing the bolts.
The earlier cars didn't have bolts, but instead had droplinks that pushed onto large balls on each end. Removal of these droplinks sometimes requires quite a bit of force to pull them off. Use a pair of vise-grips or channel locks on the droplinks for more leverage. Remove the older, worn out bushings and replace them with brand new ones, keeping in mind to spread some grease on the inside of them.
The rear sway bar bracket on the later cars is quite notorious for cracking and breaking. If you are experiencing an annoying rattle coming from your rear suspension, then you might want to check this bracket. Shake the rear sway bar, and see if the bracket is loose. There is an upgraded factory bracket for the rear sway bar that can easily be welded into the original mounting spot on the chassis, and should be significantly stronger than the original mount.
The front sway bar bushings are mounted on the a-arms and a bracket that attaches to the mounting points for the rear belly pan. The a-arm sway bar bushings are inserted into a metal bracket that is welded onto the top of the a-arm. The arrow points to the bolt that attaches the a-arm to the cross member. This is one of the bolts that needs to be removed in order gain enough maneuverability to remove the sway bar from the a-arm bushing.
The rear sway bar is attached to the car chassis with a large bracket that has a tendency to break. The drop links (shown by arrow) for the sway bar contain two rubber bushings that wrap around two mounting bolts. Replacement of these bushings simply involves the removal of the bolts, and the substitution of the old bushings with the new ones.