Replacing the Saab 9000 Rear Anti-roll Bar Bushes

Introduction

The Saab 9000 is fitted with front and rear anti-roll bars (sway bars). Their purpose of these is to tend to keep the left-hand and right-hand wheels level during cornering. This action depends on both the torsional stiffness of the anti-roll bar and the rigidity of its mountings. The standard rubber mountings are far from rigid and I purchased polyurethane replacements from SuperFlex in the hope of improving the anti-roll characteristics.

The result of replacing the rear anti-roll bar bushes on their own (without replacing the front anti-roll bar bushes) was much more marked than expected. The car's tendency to understeer is much reduced, making the handling more neutral and allowing slightly higher cornering speeds. The first time I took a roundabout at speed, I almost touched the central kerb since the understeer I was so used to had gone, while I was still expecting to have to "tug" the car round.

I am led to believe that performing the same modification to the front anti-roll bar will re-introduce understeer.

This procedure documents removal and replacement of the rear anti-roll bar bushes.

Time required

About 20 minutes: 5 minutes to jack up and remove the wheels, 5 minutes for each bush and 5 minutes to refit the wheels and lower the car.

Tools required

I assume some basic tools, such as a jack, axle stands, socket set, etc. However I do not assume you will already have all the necessary metric socket and spanner sizes, especially if you are in the USA. Here is a list so you can make sure you have all the necessary sizes before you start.

Sockets

• 10mm

Procedure

1. Slacken the rear wheel nuts.
   
   
2. Jack up the rear of the car and place it on axle stands. If you are not sure where you can safely place the jack and axle stands on a 9000, go here for more information.
   
   
3. Remove the rear roadwheels.
   
   
4. Ensure the rear suspension is hanging freely with no load on it, then for each mounting:
   
   
   1. Remove the two 10mm bolts securing the u-clamp. Note how much play there is in the standard rubber bush. This play is even more noticeable when the suspension is loaded - the bushes (at least on my car after 150K miles) are very soft compared to the polyurethane replacements. I took the precaution of spraying penetrating lubricant on the bolts, although in my case, I think it probably wasn't necessary.
      
      
      
      
   2. Remove the u-clamp and bush.
      
      
   3. If fitting Superflex polyurethane bushes, lubricate the inside of the new bush with the supplied lubricant. Fit the bush over the bar (it isn't apparent from the photographs, but each bush has a cut in it to enable it to slip over the anti-roll bar) and place the u-clamp over the bush.
      
      
   4. Refit the 10mm bolts. The Haynes manual recommends torquing them to 85Nm (63lbft), but I found that I couldn't apply this much torque without twisting the bracket more than I thought was healthy. I simply did them up tightly.
      
      
      
      
5. Refit the roadwheels.
   
   
6. Lower the car.
   
   
7. Torque the roadwheel bolts to 115Nm (85lbft).