Suspension & Steering (A4)

Rack-and-pinion and recirculating-ball systems may be power-assisted hydraulically or electrically.

Steering effort that is heavy in only one direction points to an internal steering-gear or valve fault.

Worn tie rod ends cause play, toe changes, wandering, and feathered tire wear, and must be replaced before alignment.

Worn shocks or struts allow the body to keep bouncing after a bump and can cause tire cupping.

The stabilizer (sway) bar reduces body roll during cornering; worn links or bushings produce clunks.

Ball joints are inspected for excessive axial and radial play and can fail catastrophically if neglected.

Camber is the inward/outward tilt of the wheel viewed from the front; a side-to-side difference causes a pull.

Caster is the forward/rearward tilt of the steering axis; positive caster improves stability and steering return.

Toe is the most critical angle for tire wear; incorrect toe causes rapid feathered wear, and an off-center wheel indicates an unequal toe split.

Under-inflation wears both tire shoulders while over-inflation wears the center; correct pressure prevents both.

Wheel/tire imbalance produces a vibration at a specific speed, corrected by static and dynamic balancing.

Replacement tires must meet the vehicle's load index and speed rating, and rotation promotes even wear.

Included angle equals camber plus SAI and helps detect bent spindles or struts when it differs side to side.

A pull can result from a cross-camber or cross-caster difference, or from a defective tire.

Always repair worn steering and suspension parts before performing a wheel alignment.