420motorsport. Suspension & Chassis – Shocks, Bushings, Steering Parts

What suspension, steering and chassis parts do

The running gear determines how the tyres keep contact with the road and how calmly the car reacts to bumps, braking and cornering. Among the suspension parts you will find, for example, ICON shock absorbers for Toyota Tundra, GM HD and Ford F-250/F-350, as well as coilover kits where spring and damper are combined in one unit. Bilstein and KYB are also among the brands in the category. Other parts affect geometry and stiffness, such as ICON's adjustable track bar, camber bolts for wheel alignment or the QA1 Transmission X-Brace, a cross brace at the transmission. See also steering and chassis parts.

How to choose suspension

Start with the car and how you use it. For a pickup or off-road vehicle, the lift is crucial: the ICON shocks, for example, are divided by lift such as 0-1.5 or 4.5 inches, and the wrong length can limit travel or put strain on the shock. For street cars and the track, it is more about damping, spring rate and adjustment. Weigh up several factors:

Use: daily driving, towing, off-road and track place different demands on comfort and control.

Ride height: a changed height may require a new wheel alignment, caster correction, e.g. with the Old Man Emu Caster Kit, or an adjustable track bar.

Adjustment: adjustable shocks allow fine-tuning, but it takes time to find the right setting.

The whole picture: new springs rarely give the desired result if the shocks or bushings are worn.

Bushings and mounts – material and fit

Bushings and mounts absorb movement between arms, axles and body. They are typically available in rubber or polyurethane. Polyurethane can give more precise steering, but can also transmit more vibration and noise. The category includes, for example, the Old Man Emu Bushing Kit and Rugged Ridge bushings for the track bar on the 1987-95 Jeep Wrangler YJ, and Superpro and Moog are also among the brands. Check model year, drivetrain and front or rear position, as many parts are specific. The ICON parts for F-250/F-350, for example, are divided by 4WD and lift.

Installation, wheel alignment and inspection

Suspension and steering parts directly affect safety, so installation requires the correct tools and the right tightening torques. Rubber bushings are often only fully tightened once the car is standing on its wheels at normal ride height. Have a wheel alignment carried out after the work. Whether the modification requires an inspection or approval depends on the product and the car. Therefore, check the documentation for the specific part number before you install.

Frequently asked questions

Should shock absorbers be replaced in pairs?

Shock absorbers are typically replaced in pairs on the same axle so that damping is equal on both sides. Uneven damping can cause the car to behave unevenly under braking and in corners.

When do polyurethane bushings make sense instead of rubber?

Polyurethane can be relevant if you prioritise precision and less movement in the arms, e.g. for the track or heavy loads. For pure comfort, rubber may be better, as polyurethane typically transmits more vibration and noise.

Does raising or lowering the car require an inspection?

It depends on the extent of the modification, the product and the car. Check the documentation for the specific part number and the applicable rules before you install. A changed ride height can also affect headlight alignment and wheel alignment.

What does a caster kit do?

A caster kit corrects the wheel's caster angle, which can change when the car is raised. Too little caster can result in unstable and light steering at higher speeds. The need depends on the car and how much it has been raised.

Chassis & Suspension