Rear Suspension: Intro
The rear suspension on 9-5 wagons wears out very quickly and causes the rear tires to go into huge negative camber.
This huge negative camber in turn causes tires to cup on the inside.
For those that have never experienced this problem, it causes bad vibration and noise and cannot be fixed with a rotation.
Once a tire cups, you have to deal with it until you replace the tires. To avoid the cupping as much as possible, you should rotate your tires every 3,000 miles.
It is a pain, but it does help keep tire wear more even.
Aero suspensions have even more negative camber dialed in from the factory due to the lowered suspension. I believe the stock negative camber on an Aero car is -1.1 degrees.
On my car, with worn bushings, I was running over -2 degrees. This camber gets even more negative as more weight is added to the rear.
I ruined my tires in about 15,000 miles carrying 5 people around from race to race.
If you want to carry a lot of weight and save your tires,
your best bet is to replace the bushings at 100,000 miles minimum and put in some shims to bring the camber more positive.
Then with the added weight you should be less negative than before. Some handling will be sacrificed with the camber change,
however how fast are you really going to go with 5 people in the car?
You can pick up these shims at Genuiune SAAB.
They are only a few dollars a piece and come in two sizes to give you the most amount of options.
Replacing the shocks and springs is very easy at the rear and is covered in step 1.
Replacing the bushings are covered in step 2.
The shocks require a spring compresser and the bushings require either special SAAB tools or a press.
I used a 12 ton press and the entire job went very smoothly.
A press is a good investment for the regular DIYer. It doesn't take up much space, but allows you to tackle many projects easily.
You also need a good torque wrench at the Haynes manual for torque specs. The specs change between years, so I am not going to give those specs here.
The Step 1 tab covers the rear shocks and springs.
Steps 2, 3 and 4 cover the rear bushings.
Step 5 covers installing only the rear camber shims.