Geometry Correction

Geometry correction parts restore suspension and steering angles that change when a car is lowered, and firm up mountings that move under load. The range holds a front roll-centre adjuster, geometry correction spacers, a front steering rack brace and brake master cylinder stoppers.

On many front ends, lowering raises the outer end of the lower arm relative to its inner pivot. As the arm levels out and then slopes up towards the wheel, the roll centre drops, sometimes below ground level. The body rolls more on the same springs, camber gain in bump turns the wrong way, and the changed tie rod angle brings bump steer.

Roll-centre adjusters and correction spacers reposition a pivot, usually at the outer end of the lower arm, to bring the arm back towards its designed angle. A rack brace holds the steering rack more firmly in its mounts, so the housing shifts less under cornering loads. A master cylinder stopper braces the brake master cylinder, which otherwise moves forward as the bulkhead flexes under hard braking, adding pedal travel.

Choose by the problem to solve:

• Ride height: roll-centre adjusters and spacers matter most when the lower arms sit level or slope up towards the wheel.
• Steering feel: a rack brace suits cars whose rack shifts in rubber-isolated mounts under load.
• Pedal feel: a master cylinder stopper helps a soft, long pedal once fluid, pads and hoses are known to be in good order.
• Vehicle: every part is listed for named models, so match the title and note what else has been changed on the car.

Use the fixings specified for each spacer or adjuster, and torque them to the stated figure. Check that the ball joint boot, driveshaft and wheel still clear everything at full lock and full bump. Set a stopper so it touches the master cylinder without pushing it, then check pedal travel and brake operation before driving.

Finish any geometry change with a full alignment, a bump steer check where possible and a road test. Recheck every fixing once the car has covered a few journeys.