Suspension Strut Buying Guide

MacPherson strut construction

A MacPherson strut consists of a hydraulic damper unit (shock absorber) housed inside a coil spring, with the upper end mounting to the inner wing via a top mount bearing and the lower end bolted to the steering knuckle. Because the strut carries both suspension and steering loads, its condition directly affects both ride comfort and steering precision.

On most front-wheel-drive vehicles the MacPherson strut is the dominant design. Rear MacPherson struts are also common on modern compact cars. Multi-link rear suspension replaces the strut with separate dampers and links on more sophisticated vehicles.

Signs of worn struts

A bounce test gives a basic indication — push down sharply on a corner of the car and release. A good strut damps the motion in one or two cycles; a worn strut allows continued bouncing. More reliable indicators are oil leaking from the strut body, visible pitting or corrosion on the damper rod, and handling that feels vague or wallowy. Noise over bumps often comes from the top mount bearing rather than the strut body itself.

Uneven tyre wear — particularly cupping or scalloping across the tread — is caused by the wheel bouncing on the road surface rather than maintaining steady contact, a sign of insufficient damping.

• Oil leak from damper body
• Excessive bounce after hitting a bump
• Wallowy or imprecise handling
• Clunking or knocking over bumps (often top mount bearing)
• Cupped or scalloped tyre wear

Replacement notes

Replace struts in axle pairs where possible. Replacing a single strut leaves mismatched damping on one axle, which affects straight-line braking and cornering balance. Spring compressors are required during disassembly — this is safety-critical work and the springs store substantial energy. After replacement, wheel alignment must be checked and reset. Use the registration lookup to find the correct strut assembly for your vehicle.

Frequently Asked Questions