Tyre Service and Wheel Alignment

Introduction

Tyre Service and Wheel Alignment is a practical course for apprentices, trainees, and vocational students who are learning to inspect tyres, service wheel and tyre assemblies, balance wheels, diagnose wear patterns, and carry out wheel alignment safely and accurately. You will work from vehicle and equipment manufacturer data rather than guessing settings. The exact tyre pressure, wheel fastener torque, lifting points, tyre compatibility, alignment specifications, and calibration procedures vary by vehicle.

A professional tyre and alignment job is more than changing a tyre or making a steering wheel look straight. You need to connect the customer's complaint, tyre condition, wheel condition, steering and suspension condition, measured alignment data, and final road behaviour. Good workmanship improves safety, tyre life, ride quality, steering stability, and customer confidence.

Learning Outcomes

By the end of this course, you should be able to inspect a wheel and tyre assembly, read common tyre markings, measure pressure and tread depth, recognise important wear patterns, explain static and dynamic imbalance, use a balancing machine under supervision, explain toe, camber, caster, and thrust angle, prepare a vehicle for alignment, interpret an alignment report, carry out permitted adjustments, and document the result.

You should also be able to decide when a job must stop because of damaged components, incompatible parts, uncertain specifications, unsafe lifting conditions, or a procedure that requires specialist equipment or manufacturer-specific calibration.

Workshop Safety and Job Preparation

Tyre service combines stored air pressure, heavy rotating assemblies, lifting equipment, compressed air, bead-breaking forces, and powered workshop machines. Follow your workplace risk assessment, equipment instructions, vehicle manufacturer information, and the directions of your trainer or supervisor. Wear the required personal protective equipment and keep hands, clothing, hair, and tools clear of moving parts.

Before lifting a vehicle, confirm its mass, lifting points, lift capacity, and stability. Before removing a wheel, identify locking fasteners, wheel covers, tyre-pressure monitoring equipment, directional or asymmetric tyre markings, and any visible damage. Never rely on a jack alone when the approved procedure requires additional support. Keep the work area clean so that loose weights, valve parts, lubricant, or tools do not become slip or trip hazards.

For inflation, use serviceable equipment and follow the tyre, wheel, machine, and workplace procedure. A tyre and rim that do not match, a damaged bead, a cracked wheel, or an uncertain assembly must not be treated as a routine mounting job. Do not improvise around damaged or unfamiliar assemblies.

A Safe Service Sequence

Stage	What you check	Why it matters
Receive the job	Customer complaint, vehicle data, tyre size, warning lamps, previous repairs	Establishes the reason for service and prevents assumptions
Inspect before dismantling	Pressure, tread, sidewall, wheel, fasteners, steering and suspension clues	Preserves evidence that may explain wear or vibration
Use correct equipment	Lift, sockets, torque wrench, tyre changer, balancer, alignment system	Reduces damage and improves repeatability
Measure and compare	Manufacturer specifications and measured values	Converts observations into a defensible diagnosis
Verify after work	Torque, pressure, balance, alignment printout, warning systems, road behaviour when permitted	Confirms that the service has achieved its purpose

Tyre Construction and Identification

A modern pneumatic tyre is a flexible structure that carries load, transmits driving and braking forces, contributes to cornering, absorbs road irregularities, and keeps a controlled contact patch with the road. Important parts include the tread, belts, carcass or body plies, sidewalls, beads, and inner liner. Damage in one area can affect the whole assembly.

The sidewall carries information used during service. Depending on the market and tyre, you may find nominal section width, aspect ratio, construction type, rim diameter, load index, speed symbol, manufacturer information, approval marks, production codes, and markings for tyre type or mounting orientation. Do not use the sidewall alone to decide replacement suitability: compare the tyre with the vehicle manufacturer's requirements and local regulations.

A marking such as 205/55 R16 describes a nominal tyre size: 205 is the nominal section width in millimetres, 55 is the aspect ratio as a percentage of section width, R identifies radial construction, and 16 is the nominal rim diameter in inches. Load and speed ratings appear separately. A replacement tyre must meet the applicable vehicle, wheel, axle, legal, and manufacturer requirements.

Directional, Asymmetric, and Special Tyres

Directional tyres normally have a direction-of-rotation marking. Asymmetric tyres normally identify an inside and outside sidewall. Some tyres combine special construction, run-flat capability, acoustic features, sealant systems, or vehicle-specific approvals. The correct mounting method and position depend on the marking and manufacturer instructions. Record anything unusual before dismantling.

Inspection: Pressure, Tread, Damage, and Wear

Check tyre pressure with an appropriate gauge and compare the result with the vehicle manufacturer's specified cold inflation pressure for the actual load condition. The maximum pressure moulded on a tyre sidewall is not automatically the correct operating pressure for the vehicle. Pressure changes with temperature, so record the conditions when a precise diagnosis is required.

Measure tread depth at appropriate points across the tread and around the tyre, following local rules and workplace procedures. A single measurement can miss localised wear, so look for variation. Also inspect for cuts, bulges, exposed cords, embedded objects, bead damage, ageing signs, previous repairs, and evidence of rubbing.

Reading Wear Patterns

Wear patterns are evidence, not a diagnosis by themselves. Compare the pattern with pressure history, wheel alignment, suspension condition, driving conditions, rotation history, tyre construction, and vehicle loading.

Observation	Possible causes to investigate	Next diagnostic step
Greater wear near both shoulders	Long-term underinflation, heavy loading, severe cornering, or other operating factors	Verify pressure history, load, tyre suitability, and alignment
Greater wear in the centre	Long-term pressure or application mismatch may contribute	Compare pressure and tyre fitment with manufacturer information
Strong wear on one shoulder	Camber, toe, bent or worn components, or operating conditions	Inspect steering and suspension, then measure alignment
Feathered tread blocks	Toe-related scrub is one possible cause	Check for looseness or damage before measuring toe
Cupping or scalloping	Wheel imbalance, damping problems, looseness, runout, or other mechanical causes	Inspect wheel, tyre, suspension, and balance condition
Localised flat area	Lock-up, long storage, impact, or tyre damage may be involved	Confirm history and inspect the complete assembly

Do not promise a customer that alignment alone will remove an existing wear pattern. Alignment can correct a geometry fault, but it cannot restore rubber that has already worn away.

Wheel Removal and Refit

Before removing a wheel, identify the correct lifting point and fastener type. Support the wheel as the fasteners are removed so that you do not damage studs, threads, decorative surfaces, or your back. Inspect the mating faces and fasteners according to the manufacturer's procedure. Dirt, corrosion, paint build-up, damaged threads, incorrect seats, or incompatible fasteners can affect clamping.

When refitting, start fasteners by hand where the design allows, seat the wheel correctly, and use the specified tightening sequence. Final tightening should be carried out with a calibrated torque wrench to the vehicle manufacturer's specified torque unless an approved procedure states otherwise. An impact wrench can be useful for removal and controlled run-down, but it should not replace a verified final torque procedure.

Tyre Demounting and Mounting

A tyre changer applies large forces to the bead and sidewall. Before using it, identify the wheel material and finish, tyre construction, valve or tyre-pressure monitoring sensor position, mounting direction, and any special instructions. Fully deflate the tyre according to the approved procedure before bead breaking. Use approved lubricant and the correct machine attachments.

During mounting, keep the bead correctly positioned in the wheel well and protect the bead, rim, and sensor. Stop if the bead does not behave normally or the tyre and wheel appear incompatible. Inflation and bead seating must follow the tyre changer, tyre, wheel, and workplace instructions. Machine-specific training is essential because controls and safe zones differ between designs.

Wheel Balancing

Wheel balancing corrects unequal mass distribution in the rotating wheel and tyre assembly. An imbalance can create vibration and can increase loads on vehicle components. Balancing is different from wheel alignment: balancing deals mainly with rotating mass distribution, while alignment deals with wheel and steering geometry relative to the vehicle.

A balancer measures the assembly and indicates where correction weights should be placed. Depending on the wheel and machine, you may use clip-on or adhesive weights and different correction planes. The wheel must be mounted correctly on the balancer because centring error can create a false result. Remove unsuitable old weights when the procedure requires it, enter correct wheel dimensions, perform the measurement, fit the indicated correction, and run a verification spin.

Static and Dynamic Imbalance

Static imbalance describes a heavy spot that can make the assembly tend to bounce vertically. Dynamic imbalance involves unequal mass distribution across the width of the assembly and can create a side-to-side couple. Modern service balancing normally measures and corrects both effects using the machine's selected mode.

If repeated balancing does not cure a vibration, investigate wheel runout, tyre uniformity, centring, contamination, damage, hub condition, driveline causes, and vehicle-specific diagnostic information. A balance value of zero on the machine does not prove that every possible vibration source has been eliminated.

Wheel Alignment Fundamentals

Wheel alignment measures and, where the vehicle allows, adjusts wheel and steering geometry. The main service angles are toe, camber, and caster. Other values can include steering-axis inclination, included angle, set-back, thrust angle, total toe, individual toe, and rear-wheel geometry. The exact values and adjustment methods depend on the vehicle.

Toe

Toe is viewed from above. If the front edges of a pair of wheels are closer together than the rear edges, the condition is commonly called toe-in; the opposite is toe-out. Alignment equipment may display toe in degrees, minutes, or a linear equivalent. Always interpret the sign and unit according to the machine and vehicle specification.

Toe has a strong influence on tyre scrub. However, a measured toe error can be caused or changed by worn joints, incorrect ride height, collision damage, steering-centre errors, or movement during measurement. Correct the mechanical problem before treating the display value as an isolated adjustment.

Camber

Camber is the inward or outward inclination of a wheel from vertical when viewed from the front or rear. Positive and negative values are defined by convention. Camber affects how the tyre sits relative to the road and can contribute to one-sided wear, but camber must be interpreted together with toe, suspension design, ride height, load, and vehicle specifications.

Caster

Caster describes the fore-and-aft inclination of the steering axis when viewed from the side. It contributes to steering stability, self-centring, steering feel, and camber change during steering. On many vehicles caster is not routinely adjustable without moving or replacing components, so a large side-to-side difference can be a diagnostic clue rather than a simple adjustment instruction.

Rear Geometry and Thrust Angle

Rear-wheel alignment can influence the direction in which the vehicle tracks. The thrust angle describes the direction of the rear axle or rear-wheel thrust line relative to the vehicle reference. On a four-wheel alignment, rear geometry is normally assessed before final front toe because the rear thrust line affects steering-centre interpretation.

Preparing a Vehicle for Alignment

Alignment accuracy depends on preparation. Confirm the complaint and vehicle identity, then check tyre sizes, pressure, condition, wheel condition, wheel bearing play, steering and suspension joints, ride height where specified, and vehicle loading requirements. Correct faults that make the measurement unreliable before adjusting alignment.

The alignment rack must be level and the equipment must be calibrated and used according to its manufacturer instructions. Position the vehicle correctly, fit targets or sensors without damaging wheels, compensate for wheel runout if required by the equipment, release binding in the suspension as specified, and follow the machine's sequence for caster sweep and steering-centre control.

A Typical Four-Wheel Alignment Workflow

Workflow step	Apprentice action	Evidence
Confirm specifications	Select the exact vehicle, suspension, wheel, and option data required by the equipment	Correct specification set displayed
Pre-check the vehicle	Inspect tyres, pressure, steering, suspension, wheel bearings, ride height, and obvious damage	Pre-check notes
Set up the aligner	Position vehicle and fit targets or sensors correctly	Stable live readings
Measure initial geometry	Complete the required compensation and steering procedures	Before-adjustment printout
Correct rear geometry where adjustable	Follow manufacturer sequence and torque procedures	Rear readings within required limits or documented exception
Centre steering and adjust front toe	Hold or centre the steering correctly and adjust without twisting boots or damaging parts	Front readings within required limits
Tighten and recheck	Tighten adjusters to specification and repeat measurements	Final stable readings
Complete vehicle-specific procedures	Perform steering-angle or driver-assistance calibration only where the manufacturer requires it	Calibration record where applicable
Quality check	Check steering position, warning lamps, fasteners, printout, and road behaviour when authorised	Final service record

Steering Angle Sensors and Driver Assistance Systems

Modern vehicles may use steering-angle, yaw, camera, radar, or other chassis and driver-assistance data. Wheel alignment can change the geometric relationship that these systems expect. Some vehicles require a steering-angle reset, calibration, or a broader driver-assistance calibration after alignment or suspension work; others do not. Follow the exact manufacturer procedure and use the required scan or calibration equipment.

Do not clear a warning lamp or perform a reset simply to make a dashboard message disappear. Diagnose the cause, document the work, and confirm that any required calibration completes successfully.

Diagnosis: Linking Symptoms to Tests

A strong technician does not replace parts or adjust angles from one symptom alone. Use a sequence: define the complaint, inspect, measure, compare with specification, identify the cause, correct it, and verify the result.

Customer symptom	Useful checks	Important distinction
Steering wheel off-centre	Tyre pressures, steering components, front and rear toe, thrust angle, previous repair	An off-centre wheel is not proof of front toe alone
Vehicle pulls to one side	Tyres, pressure, road crown, brake drag, alignment cross-values, suspension damage	Pull and steering-wheel position are different complaints
Vibration at road speed	Wheel balance, centring, runout, tyre condition, hub fit, driveline	Alignment is not the first explanation for most rotational vibration
Rapid shoulder wear	Pressure, toe, camber, suspension condition, use pattern	Wear can have multiple simultaneous causes
Repeated loss of pressure	Valve, bead seal, puncture, wheel damage, tyre damage	Adding air repeatedly is not a repair

Quality Control and Documentation

Professional service ends with evidence. Record tyre identification where required, tread and pressure findings, work performed, replacement parts, wheel fastener torque procedure, balance result, alignment before-and-after values, calibration work, and faults that remain. Explain the result to the customer in plain language without claiming more certainty than the measurements support.

Before releasing the vehicle, perform the checks required by your workplace and manufacturer procedure. Typical checks include pressure, valve sealing, wheel security, tool removal, warning lamps, steering position, and final alignment readings. A road test should only be completed by an authorised person under safe and legal conditions.

Environmental and Economic Practice

Correct pressure, sound wheel geometry, and timely tyre rotation where the manufacturer permits it can help tyres wear more evenly and last longer. Avoid replacing serviceable parts without evidence. Sort used tyres, wheel weights, valves, packaging, and other workshop waste according to local environmental rules. Prevent lubricant, cleaner, and tyre debris from entering drains.

Good diagnosis also saves customer time. A correctly documented cause is more valuable than repeated adjustment without finding the mechanical fault.

Interactive Tasks

Quiz: Test Your Knowledge

What is the main purpose of wheel balancing? (Correct unequal mass distribution in the rotating assembly) (!Adjust the steering axis to vehicle specifications) (!Increase tyre pressure above the placard value) (!Change the wheelbase of the vehicle)

What should you use as the primary source for the correct cold tyre pressure? (Vehicle manufacturer information) (!The highest pressure printed on any tyre) (!The pressure used on the previous vehicle) (!The balancer display)

Which alignment angle is viewed as wheel inclination from vertical at the front or rear? (Camber) (!Pressure) (!Runout) (!Balance)

Which alignment angle is viewed mainly from above and describes whether wheels point inward or outward? (Toe) (!Caster) (!Torque) (!Tread)

What should happen before alignment adjustment if a steering joint has excessive play? (The mechanical fault should be corrected) (!The toe should be set to zero) (!The tyre pressure should be doubled) (!The steering wheel should be removed)

Why is correct centring on a wheel balancer important? (It prevents mounting error from creating a false balance result) (!It changes the tyre speed rating) (!It increases the tyre load index) (!It replaces the need for wheel weights)

What is the correct approach to final wheel fastener tightening? (Use the specified torque procedure) (!Tighten until the impact wrench stops) (!Use the same torque for every vehicle) (!Apply lubricant to every fastener)

What can a feathered tread pattern suggest should be investigated? (Toe related scrub) (!A higher load index) (!A larger rim diameter) (!A newer production code)

Why can rear wheel geometry matter during a four wheel alignment? (It can influence thrust direction and steering centre) (!It sets the tyre speed symbol) (!It changes wheel balance weight) (!It determines valve stem length)

What should you do when a vehicle manufacturer requires steering angle calibration after alignment? (Complete the specified calibration procedure) (!Ignore it if the steering wheel looks straight) (!Remove the tyre pressure sensors) (!Add wheel weights to the front axle)

Memory Game

Camber	Wheel inclination from vertical when viewed from the front or rear
Caster	Fore and aft inclination of the steering axis when viewed from the side
Runout	Deviation of a rotating surface from a true circular or planar path
Balancing	Correction of unequal mass distribution in a rotating wheel and tyre assembly
Tread	Patterned outer tyre surface that contacts the road
Thrustline	Direction in which the rear wheels tend to drive the vehicle

Drag and Drop

Match the correct terms.	Topic
Manufacturer specification	Correct target value for the exact vehicle
Tread depth gauge	Tool for measuring remaining tread depth
Torque wrench	Tool for verified final wheel fastener tightening
Wheel balancer	Machine for measuring rotating mass imbalance
Alignment target	Equipment attached or referenced by an alignment measuring system

...

Crossword Puzzle

Camber	Which alignment angle describes wheel inclination from vertical?
Caster	Which angle describes fore and aft steering axis inclination?
Balance	What condition is corrected by adding approved wheel weights?
Pressure	What tyre quantity is checked with a suitable gauge?
Tread	What patterned part of a tyre contacts the road?
Runout	What term describes deviation during rotation from a true path?

LearningApps

Cloze Text

Open-Ended Tasks

Easy

Tyre Identification Walkaround: Photograph or sketch four tyre sidewalls in your training workshop, identify the service markings that you can verify, and explain what each marking tells a technician.
Pressure Measurement Practice: Under supervision, measure and record the cold tyre pressures on a training vehicle, compare them with the manufacturer information, and explain any difference.
Tread Mapping: Measure tread depth across each tyre on a training vehicle, create a simple tread map, and describe whether the wear appears even or uneven.
Tool Recognition Poster: Create an illustrated poster showing a torque wrench, tread depth gauge, tyre changer, wheel balancer, and alignment target with one safe-use point for each tool.

Standard

Wheel Service Job Card: Create and complete a professional job card for a supervised wheel removal and refit, including vehicle identification, inspection findings, specified torque, and final checks.
Wear Pattern Investigation: Select a worn training tyre, document its pattern with photographs or a drawing, propose at least three possible causes, and plan tests that would separate them.
Balancing Demonstration: Under supervision, record a short training video that explains correct mounting of a wheel on a balancer, the measurement step, correction weight placement, and the verification spin.
Alignment Report Explanation: Use an anonymised before-and-after alignment printout to explain toe, camber, caster, and thrust information to a classmate as if they were a customer.

Advanced

Vibration Diagnostic Plan: Develop a decision tree for a road-speed vibration complaint that distinguishes balance, runout, tyre condition, hub fit, and driveline causes before recommending repair.
Four Wheel Alignment Project: Under supervision, carry out a complete pre-check and four-wheel alignment on a suitable training vehicle, document every specification and adjustment, and evaluate the final readings.
Driver Assistance Calibration Research: Choose one modern training vehicle and use approved manufacturer information to determine whether alignment or suspension work requires steering-angle or driver-assistance calibration, then present the exact workflow.
Workshop Quality Audit: Audit a tyre and alignment work area for safety, calibration control, waste handling, documentation, and tool condition, then produce a prioritised improvement report supported by photographs or diagrams.

Learning Assessment

Diagnosis from Evidence: Given a vehicle with one-sided front tyre wear and an off-centre steering wheel, explain the inspection and measurement sequence you would use before making any adjustment.
Specification Control: Compare two similar vehicle variants with different manufacturer tyre pressures or alignment data and explain why selecting the exact specification matters.
Balance versus Alignment: Analyse three customer complaints and justify whether your first test should focus on balance, alignment, tyre condition, or another system.
Safe Service Planning: Write a workshop method for a wheel and tyre service that identifies stored-energy, lifting, rotating-machine, and fastener risks and shows how each risk is controlled.
Alignment Data Interpretation: Interpret a supplied before-and-after alignment report, identify which values changed, explain the likely effect, and state any result that still needs investigation.
Transfer to Customer Advice: Produce a clear customer explanation that connects measured tyre wear, pressure, mechanical condition, and alignment results without overstating what the service can achieve.

Evidence of Learning

Evidence type	What successful evidence shows
Knowledge	You can explain tyre construction and markings, pressure, tread inspection, balance, toe, camber, caster, thrust angle, and the difference between symptoms and causes.
Practical skill	You can use workshop measuring and service equipment safely under the required level of supervision, follow specifications, protect components, and verify results.
Diagnostic reasoning	You can combine customer symptoms, inspection findings, wear patterns, measured geometry, balance results, and mechanical checks before deciding on corrective action.
Product	You can produce accurate job cards, tread maps, balance records, alignment printouts, calibration records where required, and customer explanations.
Transfer	You can apply the same evidence-based method to unfamiliar vehicles by finding the correct manufacturer data and adapting to different equipment and vehicle systems.