Workshop manuals contain detailed sections on suspension and steering geometry: alignment specifications, ride heights, torque values for suspension fasteners, and inspection criteria. These specifications are what separates a properly aligned, predictable-handling vehicle from one that wears tyres unevenly and pulls in different directions over bumps.
Alignment Specifications
Three key angles are specified for both front and (on independent rear suspension) rear wheels: camber (the inward or outward tilt of the wheel from vertical, viewed from the front), caster (the forward or backward tilt of the steering axis, viewed from the side – applies to front wheels only), and toe (whether the wheels point inward or outward, viewed from above). Each has a target value with an acceptable tolerance range.
Camber is typically slightly negative (top of wheel tilted inward) on most cars – around -0.5 to -1.5 degrees – to maintain tyre contact during cornering. Caster is positive (steering axis tilted backward at the top) – typically 3 to 6 degrees – which provides steering self-centring and stability at speed. Toe is usually slightly toe-in (front of wheels closer than rear) of around 0 to 0.2 degrees per side to compensate for compliance under driving loads.
When to Check Alignment
Alignment should be checked after any suspension component replacement (struts, control arms, tie rods, ball joints), after hitting a significant pothole or kerb, when uneven tyre wear is observed, when the steering wheel is not centred on a straight road, or every 12 months as preventive maintenance. New tyres also benefit from an alignment check – alignment shops will often refuse to warranty premature tyre wear if alignment was not checked at fitment.
Ride Height Specifications
Workshop manuals specify the correct ride height (the distance from a specified body reference point to the ground, measured at all four corners). Sagging springs cause low ride height, which throws off alignment angles – particularly camber – even before any suspension components fail. Always check ride height against spec before performing alignment; an alignment on a vehicle with sagging springs will be wrong as soon as new springs are fitted.
Torque Values for Suspension Fasteners
Suspension fasteners are commonly torqued to high values: lower control arm bolts often 100 to 200 Nm, ball joint nuts 50 to 100 Nm, strut top mount nuts 40 to 80 Nm, sway bar link nuts 50 to 70 Nm, axle nuts 250 to 350 Nm, wheel nuts 100 to 130 Nm. Many suspension bolts are also “single-use” or “torque-to-yield” – they must be replaced after each removal because they stretch beyond their elastic limit when tightened. The manual notes which bolts must be replaced.
Loaded vs Unloaded Tightening
Many rubber-bushed suspension joints (control arm bushings, sway bar bushings) must be tightened with the suspension in its normal loaded position – that is, with the wheels supporting the vehicle weight. Tightening these in the unloaded position causes the bushing to be permanently twisted, leading to early failure and weird handling. The manual specifies which bolts require loaded tightening – always follow this carefully.
Inspection Limits
The manual includes inspection criteria for ball joints (maximum acceptable play), tie rod ends (lash specs), wheel bearings (free play and noise criteria), and bushing condition. Use these to make pass/fail decisions during inspection rather than guessing whether a part is “acceptable”.
For complete suspension and alignment specifications by model and year, MechanicMate offers PDF workshop manuals for over 960 models at mechanicmate.net/shop.
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