Wheel Alignment: Causes and Fixes

Understanding Wheel Alignment and its Importance

Ensuring your car's wheels are correctly aligned is fundamental for safe driving, optimal handling, and maximising the lifespan of your tyres. Wheel alignment, often referred to as 'tracking', refers to the angles of the wheels relative to the road and to each other. When these angles are not within the manufacturer's specified tolerances, it can lead to a host of issues, from premature tyre wear to compromised steering. This article will delve into how wheel alignment works, the tell-tale signs of misalignment, and what to do if your car's alignment is out of tolerance.

How Wheel Alignment Works

The steering and suspension system of a vehicle is designed to keep the wheels pointing in the desired direction. However, several factors can cause these angles to deviate. The primary angles that influence wheel alignment are:

• Camber: This is the inward or outward tilt of the top of the wheel when viewed from the front of the car. A slight outward tilt (positive camber) or inward tilt (negative camber) is often built into the suspension design to aid steering and distribute load. Incorrect camber can lead to wear on the inner or outer edges of the tyre.
• Caster: This refers to the angle of the steering axis when viewed from the side. It's responsible for the self-centring effect of the steering, making the steering wheel return to the straight-ahead position after a turn. Incorrect caster can result in vague steering or a reluctance for the steering to return to centre.
• Toe: This is the angle of the wheels when viewed from above. 'Toe-in' means the front of the wheels point slightly inwards, while 'toe-out' means they point slightly outwards. Most vehicles are set to have a small degree of toe-in to counteract the tendency of the wheels to splay outwards when in motion due to forces acting on the suspension. The track rods are the components that control this toe setting.

The system relies on the track rods, which connect the steering rack or box to the wheels. These rods not only transmit steering input but also act as braces, keeping the wheels parallel. However, due to natural play in the suspension and the flexibility of components, a precise 'toe' setting is crucial. This is typically a very small measurement, often between 1.58 mm and 6.35 mm (1/16 to 1/4 inch), and accuracy to within 0.79 mm (1/32 inch) is vital.

When to Check Your Wheel Alignment

While some car manufacturers may not explicitly list regular alignment checks in their service schedules, it's essential to have it checked under specific circumstances:

• After an Accident: Any impact, even a minor one, can affect alignment.
• After Hitting a Kerb or Pothole: Significant jolts can easily knock your alignment out.
• Following Suspension or Steering Work: If any components in these systems have been disturbed, alignment should be checked before finalising the work.
• When Fitting New Tyres: To ensure your new tyres wear evenly.
• If You Notice Uneven Tyre Wear: This is often the most obvious indicator.
• If the Steering Feels Off: Symptoms like pulling to one side, vague steering, or a steering wheel not centred when driving straight are strong indicators.

Identifying Misalignment: The Tell-Tale Signs

Several observable signs can point to your wheel alignment being out of tolerance:

Tyre Wear Patterns

This is arguably the most common and significant indicator. Look out for:

• Uneven Wear Bands: A distinct band of wear that is more pronounced than the rest of the tyre, either on the inside or outside edge of the tread. This can occur on one or both front tyres.
• Feathering: This is a subtle but distinct 'fin' effect on the edges of the tread pattern. You can check for this by running your hand across the tread from the outside edge to the inside, and then back. If it feels smooth in one direction and 'obstructs' your hand in the other, feathering is likely present. This is a strong indicator of incorrect front wheel alignment.

Steering Behaviour

Your car's handling can also reveal alignment issues:

• Pulling to One Side: If the car consistently drifts to the left or right when you're trying to drive straight, it's a classic sign.
• Steering Wheel Not Centred: If the steering wheel is off-centre when the car is travelling in a straight line, it suggests an alignment problem.
• Steering Wander or Float: A feeling of instability or that the car is not tracking true, requiring constant small corrections to the steering.
• Vague or Heavy Steering: While other issues can cause this, alignment can contribute.

Before You Start: Essential Checks

Before attempting to check or adjust your wheel alignment, it's crucial to ensure the vehicle is in the correct condition for an accurate reading. Perform these checks:

• Tyre Pressures: Ensure all tyres are inflated to the manufacturer's recommended pressures for normal load.
• Wheel Bearings: Check for any excessive play or looseness in the wheel bearings.
• Suspension and Steering Components: Inspect kingpins, ball joints, tie rod ends, and other steering linkages for wear or damage. Any worn components will render alignment readings inaccurate and the adjustments ineffective.
• Wheel Condition: Damaged or buckled wheels cannot be properly aligned.

It's important to note that while DIY tracking gauges are available, car manufacturers generally advise professional alignment checks. This is because the required precision is very high, and garages use sophisticated, calibrated equipment. However, for the determined DIY mechanic, understanding the process and using a reliable DIY gauge can be a valuable skill.

DIY Wheel Alignment Gauges

While professional equipment is expensive and complex, several types of DIY tracking gauges are available from motor accessory stores. These can provide reasonably accurate readings at a fraction of the cost.

Types of DIY Gauges:

1. Rim-to-Rim Measurement Gauges: These typically consist of two U-shaped brackets that attach to the wheel rims. They are held in place by expanding straps. You measure the distance between the ends of the brackets at the front of the wheels and then repeat the measurement at the back. The difference between these two measurements indicates the toe-in or toe-out. To convert this to a usable measurement, you might need to set the gauges on the ground to the front measurement, then measure the gap at the rear, thus providing a direct millimetre or inch reading.
2. 'Trakrite' Type Gauges: These work on a different principle, measuring the actual sideways 'scrub' of the tyre. The device has a base plate with a movable plate on rollers, linked to a dial with a pointer. As a wheel rolls over the gauge, any sideways movement (scrub) causes the pointer to register on the dial, indicating misalignment. The manufacturers of these gauges often recommend testing the vehicle under its normal load, as wheel alignment can vary with suspension compression.

How to Use a DIY Tracking Gauge

Regardless of the type of gauge used, the basic procedure involves:

1. Find a Level Surface: A flat, level area, preferably concrete, at least twice the length of your car is ideal.
2. Straighten the Vehicle: Drive the car forwards and backwards a few times to ensure it's pointing straight.
3. Position the Gauge: Place the gauge directly in front of one of the wheels, ensuring it's aligned with the centreline of the car.
4. Roll the Car: Depending on the gauge type, you may need to gently roll the car forwards or backwards over the gauge. For 'Trakrite' types, you'll typically drive forward onto the gauge and back off with hands off the steering wheel.
5. Take Readings: Record the measurements or dial readings.
6. Repeat for Other Wheels: Perform the same procedure for the other front wheel.

Adjusting Wheel Alignment

If your readings are outside the manufacturer's specifications, adjustments are necessary. This is typically done by altering the track rods.

The Adjustment Process:

1. Consult Your Manual: Find out the correct toe-in/toe-out specification for your vehicle and the specific adjustment procedure (e.g., whether to adjust one or both track rods).
2. Access the Track Rods: This may involve jacking the car up and placing it securely on axle stands for better access, or sometimes turning the steering to full lock allows access. Disconnecting the battery is a wise safety precaution.
3. Loosen Lock Nuts: Slacken the lock nuts on the track rod ends. On some cars with rack and pinion steering, you may need to loosen gaiter clips to access the lock nut.
4. Adjust the Track Rods: Adjustments are usually made equally on both sides to maintain steering balance. Turning the track rod (or its sleeve) will alter the toe setting. Make small adjustments, perhaps a quarter of a turn at a time.
5. Specific Vehicle Variations: Be aware that some vehicles have unique adjustment methods. For example, some require separating a track rod joint to rotate it, while others have single centre adjustments or adjustments on only one side.
6. Re-tighten and Re-check: Once you believe the alignment is correct, securely re-tighten the lock nuts. Bounce the front of the car several times and roll it back and forth a short distance to allow the suspension to settle. Then, re-check the alignment with your gauge.

Dealing with Seized Components:

If track rods or their sleeves are rusted and seized, soak the assembly with a penetrating fluid and allow it to work. Gently try to move the rod back and forth with a wrench. If they remain seized, the entire assembly may need replacement.

Consequences of Misalignment

Even minor misalignments can have significant consequences:

• Reduced Tyre Life: Misalignment can drastically reduce tyre life, potentially by thousands of miles.
• Compromised Handling and Safety: Incorrect alignment can lead to steering instability, making the car harder to control and potentially creating a 'semi-skid' situation, affecting safety.
• Increased Fuel Consumption: While often a secondary effect, increased rolling resistance from misaligned wheels can slightly impact fuel efficiency.

Frequently Asked Questions

Q1: How often should I check my wheel alignment?
It's best to check it after any significant impact (kerb, pothole, accident), after suspension work, or if you notice any signs of uneven tyre wear or steering issues.

Q2: Can I adjust wheel alignment myself?
Yes, with the right tools and knowledge, DIY adjustment is possible. However, precision is key, and professional checks are often recommended for accuracy.

Q3: What is the most common sign of bad wheel alignment?
The most common sign is uneven tyre wear, particularly on the edges of the tread, or feathering of the tread pattern.

Q4: Does wheel alignment affect steering?
Absolutely. Misalignment can cause the car to pull to one side, make the steering feel heavy or vague, or prevent the steering wheel from returning to centre correctly.

Q5: What is the difference between 'tracking' and 'wheel alignment'?
The terms are often used interchangeably. 'Tracking' specifically refers to the 'toe' setting (how much the wheels point in or out), while 'wheel alignment' is a broader term encompassing all the relevant angles (camber, caster, and toe).

By understanding the principles of wheel alignment and being vigilant for the signs of misalignment, you can ensure your vehicle handles correctly, your tyres last longer, and your driving experience remains safe and enjoyable.

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