What Causes a Car to Knock When Turning?
The most common causes of a knocking noise when turning are CV-joint wear, suspension bushes, ball joints, strut top mounts, track rod ends, anti-roll bar links, wheel bearings, steering components or loose wheel fittings. The exact cause depends heavily on when and how the noise occurs.
A repeated click or knock on full lock under power makes an outer CV joint more likely. A dull clunk over bumps or during weight transfer points more towards suspension bushes, joints or links. A knock that begins immediately after a pothole or wheel work deserves faster inspection because wheel, tyre, steering or suspension security may be involved.
Repeated Clicking or Knocking
Often points towards an outer CV joint, particularly if the noise is worse while accelerating slowly through a tight turn.
Dull Clunk While Turning
Suspension bushes, anti-roll bar links, ball joints, lower arms and strut mounts become more likely.
Knock With Loose Steering
Track rod ends, ball joints, steering rack components and suspension joints require prompt inspection.
Noise After an Impact
Inspect the tyre, wheel, lower arm, bushes, ball joint, track rod end, bearing and alignment after a substantial pothole or kerb strike.
Knock After Tyre Replacement
Wheel fittings, seating, tyre clearance and any component disturbed during the work should be checked before normal driving continues.
Hum or Rumble While Turning
Wheel bearings more commonly hum or rumble than knock, but lateral steering load can make a worn bearing change sound.
| When the noise happens | More likely area | Best next check |
|---|---|---|
| Repeated clicking on full lock | Outer CV joint | Inspect CV boot, grease leakage and joint behaviour |
| Dull knock over bumps while turning | Suspension links, bushes or joints | Inspect for play and damaged rubber |
| Knock while steering stationary | Top mount, steering joint or rack | Observe movement while steering is operated |
| Knock during braking and turning | Bushes, suspension arm, brake or wheel movement | Check loaded suspension and brake security |
| New knock immediately after pothole | Wheel, tyre, suspension or steering damage | Inspect impact area before regular driving |
| New knock immediately after wheel work | Wheel fitting or recently disturbed component | Check wheel security urgently |
“My car knocks when turning” is useful, but “it repeatedly clicks from the front left on full lock while accelerating” is much more diagnostic. Steering angle, speed, power application, bumps and braking help separate the possible causes.
Avoid normal driving if the steering becomes loose or unpredictable, the car pulls strongly, the wheel visibly moves, vibration becomes severe or you suspect a wheel, steering or suspension component is insecure.
How Mechanics Diagnose a Knocking Noise When Turning
A knocking noise when turning should be diagnosed by reproducing the exact condition that makes the sound appear and then changing one variable at a time. Steering angle, vehicle speed, acceleration, braking, road bumps and recent repair history all help narrow the fault.
The aim is to decide whether the knock is mainly coming from a driveshaft joint, steering component, suspension joint, wheel bearing, brake assembly or wheel fitting before parts are replaced.
1. Reproduce the noise
Confirm whether it happens on full lock, gentle steering, over bumps, while braking, during acceleration or only at parking speeds.
2. Identify the corner
Decide whether the sound seems to come from the front left, front right, rear or centre of the vehicle.
3. Compare steering angle
A noise that only appears near full lock points in a different direction from one that appears during small steering corrections.
4. Add acceleration
If the knock becomes a repeated click while power is applied through a tight turn, the outer CV joint becomes much more relevant.
5. Compare road bumps
If the noise is worse on uneven roads, inspect suspension links, bushes, ball joints and mountings for play.
6. Apply the brakes
A knock that changes under braking can involve suspension movement, brake hardware, wheel movement or loose components.
7. Inspect recent work
If the noise started after tyres, brakes, suspension or wheel work, check anything disturbed during the repair.
8. Confirm physical play
The final diagnosis should be supported by visible wear, abnormal movement, damaged rubber, loose fasteners or roughness in the suspected component.
A knock only on full lock under power suggests a different system from a knock over bumps or a clunk that appears while braking and turning.
Why Turning Changes the Load on Steering, Suspension and CV Joints
When a car turns, several forces change at the same time. The front wheels move through an angle, the suspension loads one side differently, driveshaft joints articulate, tyre contact patches change and steering joints move through their working range.
This is why a worn component may stay quiet while driving straight ahead but knock as soon as the steering is turned. The extra movement or load exposes clearance that is not obvious in straight-line driving.
CV Joint Angle Increases
Outer CV joints operate at greater angles during tight steering, which is why worn joints often become noisy on full lock.
Weight Transfers Side to Side
Bushes, ball joints and mounts are loaded differently as the vehicle changes direction.
Joints Move Through Their Range
Track rod ends, rack joints and top mounts move as the steering angle changes and can reveal play or binding.
Bearing Load Changes
Cornering changes lateral force through the wheel bearing, which can alter humming, rumbling or roughness.
Components Shift Under Load
Loose pads, caliper hardware or shields can move slightly as steering and braking forces change.
Scrub Increases at Low Speed
Wide tyres, high steering angle and certain surfaces can create tyre scrub that should not be confused with a heavy metallic knock.
What Causes Knocking When Turning?
The most common causes are wear or movement in components that carry steering, suspension or drivetrain load. The sound alone cannot prove which part has failed, so each cause should be matched to the exact operating condition.
Outer CV Joint
Commonly causes repeated clicking or knocking on full lock, especially under acceleration.
Suspension Bushes
Worn bushes can clunk as the suspension shifts during turning, braking and acceleration.
Ball Joint
Excessive ball-joint play can create knocking and may also affect steering accuracy and tyre wear.
Track Rod End
Wear can produce clunks, looseness and inaccurate steering as the wheel changes direction.
Anti-Roll Bar Link
Often causes repeated knocking over small uneven surfaces and can sound worse while turning.
Strut Top Mount
Can knock, pop or creak as the steering turns and the spring/strut assembly rotates.
Wheel Bearing
More often hums or rumbles, but noise can change as steering alters lateral load.
Steering Rack or Joint
Internal rack wear, mounting movement or steering-joint play can create knocks during steering input.
Brake or Wheel Movement
Loose caliper hardware, wheel fittings or other recently disturbed parts can knock as loads change.
Outer CV Joint Knocking or Clicking When Turning
The outer CV joint allows the driveshaft to transfer power while the wheel is steering and moving with the suspension. When the joint wears, the internal tracks and bearings can develop clearance that becomes most noticeable at high steering angles.
Typical Sound
Repeated clicking, clacking or knocking from one front corner.
Typical Condition
Tight low-speed turns, especially while accelerating out of a parking space or junction.
Useful Visual Clue
A split CV boot with grease around the driveshaft, wheel or inner arch strongly supports CV-joint wear.
A worn outer CV joint often produces a rhythmic click or knock as the wheel rotates through a tight steering angle, rather than one isolated clunk.
Can Suspension Bushes Cause Knocking When Turning?
Yes. Suspension bushes isolate movement between metal components while controlling wheel position. As rubber deteriorates or separates from its sleeve, the suspension arm can move more than intended and produce a dull knock or clunk.
Knock During Weight Transfer
Worn bushes often knock when braking, accelerating or changing direction because the suspension arm shifts.
Uneven Tyre Wear
Excessive bush movement can alter wheel geometry and contribute to uneven tyre wear.
Steering Instability
Severe wear can make the vehicle feel vague or less stable during braking and cornering.
Ball Joint Knocking When Turning
Ball joints allow steering and suspension movement while holding the wheel assembly securely in position. Once wear creates excessive play, the joint can knock as load changes.
Knock or Clunk
Movement in the joint may be heard over bumps, while turning or when braking load shifts through the wheel.
Steering Changes
Excessive wear may produce looseness, wander or imprecise steering.
MOT Relevance
Excessive ball-joint wear can affect the MOT because it is a safety-critical suspension component.
Ball Joint MOT Guide →Track Rod End Knocking When Turning
Track rod ends connect steering movement from the rack to the road wheels. Wear in the joint can create knocking, steering looseness and alignment changes.
Knock With Steering Input
Free play may become audible as the steering changes direction.
Steering Play
A worn track rod end can contribute to vague or delayed steering response.
Alignment Changes
Excessive movement can contribute to poor tracking and uneven tyre wear.
Track Rod End MOT Guide →Anti-Roll Bar Link Knocking When Turning
Anti-roll bar links connect the anti-roll bar to the suspension. Their small ball joints can wear and produce a light repetitive knock, especially over rough surfaces.
Small Sharp Bumps
Worn links often knock most clearly over broken road surfaces rather than large smooth suspension movements.
Turning on Uneven Roads
Steering while one wheel moves more than the other can make worn links more noticeable.
MOT Condition
Excessive wear can affect MOT results depending on condition and security.
Anti-Roll Bar Link MOT Guide →Strut Top Mount Knocking, Popping or Creaking When Turning
On many front suspension systems, the strut top mount carries vehicle load while also allowing the strut assembly to rotate as the steering turns.
Knock or Pop
Worn rubber or bearing components can knock as load passes through the top mount.
Spring Twang
A seized or rough top bearing can cause the spring to wind up and release suddenly while steering.
MOT Relevance
Excessive movement, insecurity or deterioration may become an MOT concern.
Top Mount MOT Guide →Can a Wheel Bearing Cause Knocking When Turning?
Wheel bearings are more commonly associated with humming, droning or rumbling that increases with road speed, but badly worn bearings can develop play and produce additional noises.
Road-Speed Hum
Noise usually becomes more obvious as speed increases.
Noise Changes in Corners
Lateral load during turning can change the bearing sound.
Excessive Play
Significant bearing movement is a safety concern and can affect MOT condition.
Wheel Bearing MOT Guide →Steering Rack or Steering Joint Knocking
Steering racks, inner joints, mountings and steering-column joints can produce knocks if wear or movement develops. Steering-system noise deserves prompt attention where it is accompanied by looseness or poor directional control.
Knock While Changing Direction
Play may become noticeable as steering force changes from left to right.
Rack Mounting Movement
Loose or deteriorated mountings can allow the rack housing to shift under steering load.
Loose Steering Feel
If the knock is accompanied by free play or delayed wheel response, arrange prompt inspection.
Brake Movement, Loose Wheel Fittings and Other Urgent Causes
Not every turning knock comes from suspension wear. Brake hardware, loose wheel fittings and components disturbed during recent work can also move under steering or braking load.
Loose Wheel Fittings
Incorrectly tightened wheel bolts or nuts can allow wheel movement and must be treated as urgent.
Loose Caliper Hardware
Caliper bolts, pad clips or other brake hardware can knock if not correctly secured.
Brake Shield Contact
A bent backing plate or shield can touch the disc and create scraping or light knocking as the wheel moves.
Knocking or Clicking on Full Lock
A repeated knock or click at full steering lock is one of the strongest clues for outer CV-joint wear, particularly on front-wheel-drive vehicles.
The joint is operating at a large angle while also transferring drive torque, which exposes internal wear more clearly than straight-line driving.
- ✓ Noise is worse while accelerating through a tight turn.
- ✓ Repeated clicking or knocking comes from one front corner.
- ✓ Grease is visible around the driveshaft or inner wheel arch.
- ✓ The noise is most obvious in car parks or tight manoeuvres.
Top mounts, steering joints and tyre scrub can also become more noticeable near full lock. The pattern should be confirmed before a driveshaft is replaced.
Low-Speed Knocking When Parking or Manoeuvring
Parking-speed manoeuvres place high steering angle and low-speed suspension load through the front of the vehicle. This can make worn joints and mountings easier to hear than at higher speeds.
Knock over bumps
Inspect anti-roll bar links, bushes, ball joints, suspension arms and strut mounts.
Knock while steering stationary
Top mounts, steering joints and rack movement become more relevant.
Knock while braking and turning
Suspension-arm bushes, brake movement and wheel security should be checked.
Repeated click under power
Outer CV-joint wear becomes more likely.
Knocking When Turning Left vs Turning Right
Turning direction can provide useful information because load shifts across the vehicle, but it does not reliably identify the failed side by itself.
Noise can travel through the subframe, suspension and body, and different faults respond differently to lateral load. Treat direction as one clue rather than a complete diagnosis.
Louder Turning Left
The right side of the vehicle generally carries more cornering load, but CV joints, steering joints and mounts can behave differently. Inspect both sides.
Louder Turning Right
The left side generally carries more cornering load, but the noisy side should still be confirmed physically.
Direction, speed, steering angle and whether power is being applied can significantly shorten diagnostic time.
Knocking When Turning After Hitting a Pothole or Kerb
A pothole or kerb strike can damage more than the tyre. Wheel, suspension and steering components can absorb substantial impact loads and may develop immediate or delayed symptoms.
Tyre Damage
Check for sidewall bulges, cuts, exposed cords or sudden pressure loss.
Tyre Bulge Guide →Bent Wheel
A wheel can deform after a heavy impact and create vibration, steering shake or clearance problems.
Steering Wheel Shake →Lower Arm Damage
Lower arms and bushes can bend, tear or develop play after impact.
Lower Arm MOT Guide →Track Rod / Steering Damage
Steering components can bend or develop play after a severe impact.
Wheel Bearing Damage
A bearing may become noisy or develop roughness after a substantial pothole strike.
Wheel Bearing MOT Guide →Alignment Change
An off-centre steering wheel or new pulling behaviour can indicate geometry has changed after the impact.
Wheel Alignment Guide →If the vehicle develops a loud knock, tyre damage, steering pull, vibration or an unstable wheel feeling after a pothole or kerb strike, avoid regular driving until the affected corner has been inspected.
Knocking After Tyre, Brake, Wheel or Suspension Work
A new knock that begins immediately after work has been done should be checked promptly. Newly fitted parts can settle, but a heavy knock or clunk should never simply be assumed to be normal.
After Tyre or Wheel Work
Check wheel fittings, wheel seating, tyre size, balancing weights and whether the tyre or wheel is contacting anything.
After Brake Work
Caliper bolts, pad hardware, retaining clips and shields should be checked if knocking or rattling begins after brake repairs.
After Suspension Work
Check fastener torque, bush orientation, ball-joint security, top mounts and whether alignment was required after the repair.
If the sound began after tyre, wheel, brake or suspension work, return the vehicle for inspection before regular driving—especially if the knock is heavy, the steering feels different or wheel security is uncertain.
Professional Diagnostic Workflow for Knocking When Turning
A good diagnosis should reproduce the knock before any parts are replaced. Steering and suspension noises can travel through the subframe, body and floor, so the component that sounds closest to the driver is not always the component actually causing the noise.
The technician should first establish whether the noise is controlled mainly by steering angle, road speed, acceleration, braking, suspension movement or a combination of these conditions. That behaviour determines which parts deserve inspection first.
1. Confirm the complaint
Ask when the knock occurs, which side it appears to come from, how long it has been present and whether anything happened shortly before it started.
2. Check recent history
Pothole impacts, kerb strikes, tyre changes, brake repairs and suspension work can significantly change the order of inspection.
3. Perform a controlled road test
Reproduce the knock using gentle turns, tight turns, braking, acceleration and suitable uneven road surfaces.
4. Compare full lock
Repeated clicking or knocking under power at high steering angle increases suspicion of an outer CV joint.
5. Compare suspension movement
A dull clunk over small bumps directs attention towards links, bushes, ball joints, arms and top mounts.
6. Compare braking load
If braking changes the knock, inspect suspension-arm movement, wheel security and brake components as well as steering joints.
7. Raise the vehicle
Inspect the wheel, tyre, brakes, steering joints, suspension joints, bushes, CV boots and wheel bearing.
8. Confirm before repair
The suspected component should explain both the physical wear found and the exact condition that produced the knock during the road test.
Finding a slightly worn component is not enough if its behaviour does not match the complaint. The best diagnosis links the road-test symptom directly to physical evidence.
How a Mechanic Road-Tests a Knocking Noise When Turning
The road test should reproduce the fault safely without unnecessarily loading a potentially damaged steering or suspension component. Each test condition should be changed separately so the technician knows which input affected the noise.
Straight Road Baseline
Establish whether the vehicle knocks, vibrates, pulls or produces wheel-bearing noise while travelling straight ahead.
Gentle Left and Right Turns
Compare the sound as lateral load transfers from one side of the vehicle to the other.
Tight Low-Speed Turns
Useful for reproducing CV-joint clicks, top-mount noises and steering-related knocks.
Gentle Acceleration While Turning
Applying drive torque helps reveal worn outer CV joints and excessive drivetrain movement.
Braking While Turning
This changes suspension-arm, brake and wheel loads and can expose bush movement or insecure components.
Uneven Road Surface
Small bumps can make anti-roll bar links, bushes, top mounts and ball-joint wear easier to reproduce.
If the steering is severely loose, a wheel is visibly moving, the tyre is damaged or the vehicle became unstable after an impact, inspection should take priority over an extended road test.
CV Joint vs Ball Joint vs Bush vs Wheel Bearing Noise
Several front-end faults can produce noises during turning, but their typical behaviour differs. Comparing the noise with steering angle, road bumps, acceleration and road speed helps narrow the most likely system.
Repeated Click on Full Lock
Usually most noticeable during tight turns under power. A split boot or escaped grease strengthens the diagnosis.
Knock With Suspension Load
May knock over bumps, during braking or as steering load changes. Physical joint play is an important confirmation.
Dull Clunk During Weight Transfer
Often appears as the suspension arm moves during braking, acceleration or changes of direction.
Hum or Rumble With Road Speed
More often produces continuous rotational noise than a single knock, although severe wear may create additional movement or roughness.
| Symptom | Most likely direction | What supports the diagnosis |
|---|---|---|
| Repeated clicking on full lock under power | Outer CV joint | Split boot, escaped grease, repeatable rhythmic click |
| Dull clunk over bumps while steering | Suspension joint, bush, link or mount | Physical play, damaged rubber or loose mounting |
| Knock with loose or vague steering | Track rod end, ball joint or steering rack | Free play during steering inspection |
| Hum that changes with road speed and cornering | Wheel bearing or tyre | Rough bearing, play or abnormal tyre wear |
| Knock only during braking and turning | Suspension arm, bush, brake or wheel movement | Component movement under braking load |
| Knock began immediately after wheel work | Wheel fitting or disturbed component | Incorrect torque, seating or insecure hardware |
What a Mechanic Checks on the Ramp
Once the road test has narrowed the likely fault area, the vehicle should be inspected physically. The technician is looking for abnormal movement, damaged rubber, looseness, roughness, impact damage and anything that could allow a component to move under steering or suspension load.
Wheel and Tyre
Check tyre damage, wheel damage, correct seating, wheel fittings, clearance and evidence of impact.
Outer CV Joint
Inspect the boot for splits, grease loss and contamination, then check the joint for excessive wear where appropriate.
Driveshaft
Check joints, shaft condition and excessive movement that could produce clunks under changing drive load.
Ball Joint
Check for excessive play, damaged boots and movement outside the intended joint range.
Track Rod Ends
Inspect inner and outer steering joints for free play, damaged boots and insecure connections.
Suspension Bushes
Look for splitting, separation, excessive movement or signs that the arm is shifting under load.
Anti-Roll Bar Links
Check link joints and mounting points for looseness or play that could create repetitive knocking.
Strut Top Mount
Observe for excessive movement, rough bearing action, spring wind-up or abnormal noise while steering.
Wheel Bearing
Check for roughness, excessive play and evidence that the bearing noise matches the road-speed complaint.
Steering Rack
Inspect rack mountings, inner joints and steering response for movement that should not be present.
Brake Components
Check caliper security, pad hardware, shields and anything that may move or contact during steering and braking.
Fasteners and Mountings
Recently disturbed suspension, brake and wheel fasteners deserve particular attention if the noise began after repair work.
Different suspension and steering designs have different normal movement. The technician should distinguish normal articulation from excessive free play before condemning a component.
What Mechanics Physically Check Before Replacing Parts
A professional inspection should confirm why a component can produce the reported knock. Visual deterioration alone does not always prove the noise source, and some worn joints can look acceptable until they are loaded correctly.
Steering Checks
- ✓ Track rod end play
- ✓ Inner steering joint movement
- ✓ Steering rack mounting security
- ✓ Column or intermediate-joint play
- ✓ Power-steering assistance where relevant
Suspension Checks
- ✓ Ball-joint play
- ✓ Lower-arm bush movement
- ✓ Anti-roll bar link wear
- ✓ Strut top mount movement
- ✓ Spring condition and seating
Wheel and Bearing Checks
- ✓ Wheel-bearing play and roughness
- ✓ Wheel damage or distortion
- ✓ Tyre bulges or impact damage
- ✓ Wheel-fitting condition
- ✓ Signs of abnormal tyre contact
Drivetrain and Brake Checks
- ✓ CV-boot condition
- ✓ Outer CV-joint wear clues
- ✓ Driveshaft movement
- ✓ Caliper and brake-hardware security
- ✓ Disc shield or backing-plate contact
Older vehicles can have several moderately worn components. The repair should target the part whose condition and behaviour actually match the customer's knocking complaint.
Mechanic-Style Knocking Diagnosis Decision Table
This table shows how the road-test clue and workshop finding should support each other before a repair decision is made.
| Road-test clue | Workshop finding | Likely diagnosis | Priority |
|---|---|---|---|
| Repeated click on full lock under power | Split CV boot or confirmed joint wear | Outer CV joint | Inspect / repair soon |
| Clunk over bumps and steering load | Excessive ball-joint movement | Ball joint | High |
| Dull clunk under braking and acceleration | Lower-arm bush movement | Suspension bush / arm | Medium–High |
| Knock with loose steering | Track rod end or steering-joint play | Steering joint | High |
| Hum or rumble changes in corners | Bearing roughness or excessive play | Wheel bearing | Medium–High |
| Knock immediately after tyre work | Loose or incorrectly seated wheel | Wheel-fitting problem | Critical |
| Knock immediately after brake work | Loose caliper or hardware | Brake-component security fault | Critical |
| Knock after pothole with steering pull | Damaged arm, joint, wheel or tyre | Impact damage | High / Critical |
Knocking When Turning Severity Guide
The severity of a knocking noise depends on the component causing it and whether vehicle control is affected. A light anti-roll bar link knock and a loose steering joint may both make similar sounds, but their safety implications can be very different.
Light Stable Noise
A quiet, occasional knock with normal steering, braking and handling may allow cautious use while an inspection is arranged.
Repeated Knock
A repeatable suspension or CV-related noise should be diagnosed before wear progresses or damages another component.
Knock With Steering Changes
Loose steering, pulling, heavy vibration or significant joint play increases the safety concern substantially.
Wheel or Component Insecurity
Suspected loose wheel fittings, loose brake hardware, major suspension movement or unstable steering should be treated as an immediate safety issue.
| Condition | Severity | Recommended action |
|---|---|---|
| Light occasional knock, normal steering and braking | Lower | Arrange inspection if persistent |
| Repeated click on full lock with normal steering | Medium | Inspect CV joint and boot soon |
| Persistent clunk over bumps with suspension play | Medium–High | Repair worn suspension component |
| Knock with steering looseness | High | Limit driving and inspect promptly |
| Knock after pothole with tyre damage or strong pull | High | Inspect before regular driving |
| Knock after wheel work with suspected loose fitting | Critical | Stop and check wheel security |
| Knock with obvious wheel movement | Critical | Do not continue normal driving |
A knock that becomes louder, more frequent or begins to affect steering, braking, tyre wear or vehicle stability should be treated more urgently than the same noise when it first appeared.
Which Fault Should Be Checked First?
Diagnostic priority should be based on safety and symptom matching rather than which component is cheapest or easiest to replace.
Wheel Security
If the noise started after tyre or wheel work, confirm wheel fitting and seating before investigating less urgent causes.
Steering Security
Track rod ends, steering joints and rack movement deserve priority when the steering feels loose or unpredictable.
Suspension Joints
Ball joints and major suspension movement should be checked quickly because they help locate and control the road wheel.
Brake Security
New noises after brake work or knocking that changes with braking should prompt inspection of the brake assembly.
CV Joint and Driveshaft
Repeated full-lock clicking with normal steering often allows a more targeted CV-joint inspection.
Lower-Level Suspension Noise
Anti-roll bar links and less severe bush noises still require repair planning but are usually assessed after wheel, steering and major suspension security.
Start with symptom matching and physical evidence. A car that clicks only on full lock should not automatically be diagnosed with a steering rack simply because steering-rack repairs are expensive.
Is It Safe to Drive With a Knocking Noise When Turning?
Whether it is safe to continue driving depends on the cause of the knock and whether vehicle control is affected. A light anti-roll bar link noise may allow cautious driving to an inspection, while a loose wheel, worn steering joint or badly worn ball joint can create a much more serious risk.
The most important safety checks are steering feel, wheel stability, braking behaviour, tyre condition and whether the knock appeared suddenly after impact or recent repair work.
Light Occasional Knock
If the noise is quiet and stable, steering feels normal and there are no other symptoms, cautious driving to an inspection may be reasonable.
Repeated Knock or Click
A repeatable CV-joint or suspension-related noise should be diagnosed before wear becomes more severe.
Knock With Steering Changes
Loose steering, strong pulling or instability suggests a steering or suspension fault that should be inspected promptly.
Wheel or Component Insecurity
Suspected loose wheel fittings, major suspension movement, severe vibration or unstable steering should be treated as an immediate safety concern.
Driving May Be Possible When...
- ✓ The steering still feels normal.
- ✓ The vehicle does not pull strongly.
- ✓ No wheel movement is visible.
- ✓ The tyres appear undamaged.
- ✓ The noise is stable rather than rapidly worsening.
Stop and Arrange Inspection When...
- ! The steering feels loose or unpredictable.
- ! The vehicle pulls heavily to one side.
- ! The wheel visibly moves or feels unstable.
- ! The knock started after wheel or suspension work.
- ! The tyre or wheel was damaged by a pothole or kerb.
- ! The noise becomes a heavy metallic clunk.
If the knocking began immediately after tyre or wheel work, do not assume it is suspension wear. Wheel fitting and seating should be checked first because an insecure wheel can become dangerous very quickly.
Typical UK Repair Costs for Knocking When Turning
Repair cost depends on which component is actually causing the knock. Some steering and suspension parts are relatively inexpensive, while complete driveshaft, suspension-arm or steering-rack repairs can cost several hundred pounds or more.
These are broad UK planning figures only. Vehicle design, labour rate, parts quality, wheel alignment requirements and seized or damaged fasteners can change the final quotation.
Anti-Roll Bar Link
£80–£220Often one of the cheaper suspension repairs where access is straightforward and no other damage is present.
Track Rod End
£100–£250Wheel alignment may be required after replacement.
Ball Joint
£120–£350Cost depends on whether the joint is replaceable separately or supplied as part of a complete suspension arm.
Lower Arm / Bush
£150–£450+Some vehicles use separate bushes while others are more economical to repair with a complete arm.
Strut Top Mount
£180–£450+Labour can increase where the strut assembly needs substantial dismantling.
CV Joint or Driveshaft
£180–£550+Some vehicles allow a CV joint to be replaced separately, while others are repaired with a complete driveshaft.
Wheel Bearing
£150–£450+Some bearings are pressed into the hub while others are supplied as complete hub assemblies.
Steering Rack Repair
£500–£1,500+Costs vary significantly between hydraulic, electric and complete rack assemblies.
Pothole / Multi-Part Repair
£150–£1,000+Repair exposure can rise quickly where a wheel, tyre, suspension arm, steering joint and alignment are affected together.
| Likely fault | Broad UK cost | Alignment likely? | Repair priority |
|---|---|---|---|
| Anti-roll bar link | £80–£220 | Usually no | Medium |
| Track rod end | £100–£250 | Often yes | High if play is excessive |
| Ball joint | £120–£350 | Sometimes | High |
| Lower arm / bush | £150–£450+ | Often advisable | Medium–High |
| Strut top mount | £180–£450+ | May be advisable | Medium |
| CV joint / driveshaft | £180–£550+ | Usually no | Medium–High |
| Wheel bearing | £150–£450+ | Usually no | Medium–High |
| Steering rack | £500–£1,500+ | Yes | High |
| Loose wheel / brake hardware | Inspection dependent | No | Critical |
Steering and suspension repairs can alter wheel geometry. When comparing prices, confirm whether wheel alignment, labour, VAT, fasteners and diagnostic charges are included.
Can Knocking When Turning Cause an MOT Failure?
The knocking noise itself is not normally what causes an MOT failure. The underlying defect matters. Excessive wear, insecurity or damage in steering, suspension, wheel-bearing or wheel components can affect the MOT result.
Ball Joint Wear
Excessive play in a ball joint can result in an MOT defect because the joint helps locate and control the road wheel.
Ball Joint MOT Guide →Track Rod End Wear
Steering-joint looseness can affect the MOT where play or insecurity exceeds acceptable limits.
Track Rod End MOT Guide →Wheel Bearing Play
Excessive bearing play or roughness can affect the MOT and should be repaired before severe deterioration develops.
Wheel Bearing MOT Guide →Suspension Defects
Worn bushes, joints, springs or mountings can become MOT defects depending on severity and security.
Suspension MOT Guide →Steering Rack Defects
Excessive steering play, insecurity or structural problems in the steering system can affect the test result.
Steering Rack MOT Guide →Wheel and Tyre Damage
Impact damage can create separate tyre or wheel defects even if the original complaint is only knocking.
Tyres and MOT →Lubricating or temporarily quietening a worn joint does not correct excessive play. The component condition is what matters for both safety and MOT assessment.
Should You Buy a Used Car That Knocks When Turning?
A used car that knocks while turning should be treated as having an unresolved steering, suspension, wheel or drivetrain fault until the source has been confirmed.
Some causes are relatively inexpensive, but others can involve several components or point towards neglected suspension and steering maintenance.
Confirmed Minor Link Noise
A diagnosed anti-roll bar link with a realistic repair quotation may be manageable if the rest of the suspension is sound.
Bush or Top-Mount Wear
These faults are often repairable but can indicate wider age-related suspension wear.
CV Joint or Driveshaft Noise
Repeated full-lock clicking should be priced before purchase and the CV boot condition checked.
Loose Steering
Knocking combined with steering free play can point to worn joints or rack-related faults and deserves careful inspection.
Pothole Damage
A car that knocks after an impact may require wheel, tyre, suspension, steering and alignment repairs together.
Seller Refuses Inspection
Refusal to allow independent inspection is a major red flag when steering or suspension noise is present.
Useful Test-Drive Checks
- ✓ Drive slowly on full left and right lock.
- ✓ Listen over small bumps.
- ✓ Check steering-centre position.
- ✓ Check whether the car pulls.
- ✓ Look for uneven tyre wear.
- ✓ Check CV boots for grease leakage.
Major Red Flags
- ! Loose or vague steering.
- ! Heavy metallic clunk.
- ! Visible wheel movement.
- ! Severe uneven tyre wear.
- ! Seller dismisses the noise without evidence.
- ! Several suspension noises are present together.
A light anti-roll bar link and a worn ball joint can both be described as a knock. Price the car using the confirmed diagnosis rather than the seller's cheapest explanation.
How to Reduce the Risk of Steering and Suspension Knocks
Steering and suspension components are wear items, so not every knock can be prevented. Regular inspection and early repair can, however, reduce the chance that small movement develops into a larger or more expensive fault.
Avoid Severe Pothole Impacts
Reduce speed safely where road conditions are poor and inspect the vehicle if a substantial impact occurs.
Maintain Correct Tyre Pressures
Correct pressures help protect tyres and reduce unnecessary wheel and suspension loading.
Check Uneven Tyre Wear
Irregular wear can be an early clue that wheel geometry or suspension condition needs attention.
Inspect Split CV Boots Early
A damaged boot can allow grease loss and contamination, accelerating CV-joint wear.
Act on New Steering Play
Free play should be investigated before it develops into more significant steering or tyre-wear problems.
Use Servicing as an Inspection Opportunity
Steering joints, suspension bushes, ball joints, tyres and wheel bearings can all be inspected during routine maintenance.
Use the Diagnostic App to Narrow the Knocking Fault
If you know when the knock happens but are not sure whether the cause is steering, suspension, drivetrain or wheel related, use the Motor Vehicle Expert Diagnostic App to narrow the next diagnostic direction.
Describe the Noise
Knocking, clicking, clunking, humming and grinding point towards different diagnostic pathways.
Add the Condition
Full lock, acceleration, braking, bumps and road speed help separate CV, suspension, steering and wheel faults.
Confirm Physically
Use the suggested pathway to decide what should be inspected before replacement parts are authorised.
The app can help narrow the likely system, but excessive play, component security and impact damage still require physical inspection.
What to Remember About Knocking When Turning
What Drivers Should Do
- ✓ Identify exactly when the knock occurs.
- ✓ Compare full lock with gentle steering.
- ✓ Check whether acceleration changes it.
- ✓ Check whether bumps or braking make it worse.
- ✓ Inspect promptly after pothole or wheel work.
- ✓ Confirm the fault before buying parts.
What Drivers Should Avoid
- ! Assuming every full-lock noise is automatically a CV joint.
- ! Ignoring loose steering.
- ! Driving with suspected loose wheel fittings.
- ! Ignoring tyre damage after an impact.
- ! Replacing several suspension parts by guesswork.
- ! Buying a noisy used car without pricing the repair.
A knocking noise when turning should be diagnosed by matching the sound to steering angle, road load, suspension movement and physical component condition. The correct repair is the component that explains both the symptom and the inspection findings.
Related Steering, Suspension and Car Noise Guides
Use these live Motor Vehicle Expert guides to move from a general knocking complaint into the most relevant steering, suspension, wheel-bearing, CV-joint, MOT or diagnostic pathway.
Car Noises Explained
Compare knocking, clicking, grinding, humming, rattling and whining noises across engine, brakes, steering, suspension, wheels and drivetrain.
Car Noises Explained →Clicking Noise When Turning
Learn why repeated clicking on full lock commonly points towards outer CV-joint wear and how to separate it from steering or suspension noise.
Clicking When Turning →Wheel Bearing Noise
Understand humming, droning and rumbling that changes with road speed and cornering load.
Wheel Bearing Noise →Car Pulls Left After Tracking
Compare tyre pull, wheel alignment and steering-related causes when the car does not track straight after adjustment.
Steering Pull Guide →Ball Joint MOT Guide
Understand how ball-joint play is assessed and when wear can become an MOT defect.
Ball Joint MOT Guide →Wheel Bearing MOT Guide
Learn when bearing play, roughness or insecurity can affect the MOT result.
Wheel Bearing MOT Guide →Suspension MOT Guide
See how worn bushes, joints, springs and other suspension defects can lead to an advisory or failure.
Suspension MOT Guide →Wheel Alignment and MOT
Understand how wheel alignment itself differs from MOT inspection and when related tyre or suspension faults matter.
Wheel Alignment MOT Guide →Diagnostics Hub
Start from vehicle symptoms and move into steering, suspension, braking, engine, clutch and electrical diagnostic pathways.
Diagnostics Hub →Diagnostic App
Use the Motor Vehicle Expert symptom pathway when you know what the car is doing but are not yet sure which system needs attention.
Open Diagnostic App →Car Servicing Guide
Understand routine inspection and maintenance that can identify steering and suspension wear before it becomes severe.
Car Servicing Guide →Used-Car Buying Guides
Check suspension condition, tyre wear, test-drive behaviour and repair risk before buying a used vehicle with front-end noise.
Used-Car Buying Guides →Car Knocking Noise When Turning FAQs
These questions cover the most common causes, safety concerns, MOT issues and diagnostic checks associated with knocking while steering.
Why does my car knock when turning?
A knocking noise when turning can come from worn CV joints, suspension bushes, ball joints, strut top mounts, track rod ends, anti-roll bar links, wheel bearings, steering components, brake movement or loose wheel fittings.
Why does my car knock on full lock?
Knocking or repeated clicking on full lock commonly points towards outer CV joint wear, especially when the noise appears during slow tight turns while power is being applied.
Why does my car knock when turning left?
Turning left changes the load through the wheels, bearings, suspension, steering and CV joints. The fault may be on either side because noise can travel through the body, so the noisy component should be confirmed by inspection rather than diagnosed from direction alone.
Why does my car knock when turning right?
Turning right changes lateral load through the suspension, steering, wheel bearings and driveshafts. A fault may become louder under this load, but the source should be confirmed with a road test and physical inspection.
Can a CV joint cause knocking when turning?
Yes. A worn outer CV joint commonly produces repeated clicking or knocking during tight turns, especially while accelerating. A split CV boot and grease around the wheel or driveshaft are useful supporting clues.
Can suspension bushes cause knocking when turning?
Yes. Worn or separated suspension bushes can knock as loads change during turning, braking, acceleration or travel over uneven roads.
Can a ball joint cause a knocking noise when turning?
Yes. Excessive ball-joint wear can create knocking or clunking as steering and suspension loads change. Significant play can also affect steering accuracy, tyre wear and MOT condition.
Can a strut top mount knock when turning?
Yes. A worn strut top mount or bearing can knock, pop, creak or twang as the steering turns and the suspension spring and strut assembly move.
Can a track rod end cause knocking when turning?
Yes. A worn track rod end can knock as steering load changes and may also cause looseness, poor alignment, uneven tyre wear or imprecise steering.
Can a wheel bearing knock when turning?
Wheel bearings more commonly hum, drone or rumble, but a badly worn bearing can produce other noises and turning can change the sound as lateral load changes.
Can a pothole cause knocking when turning?
Yes. A pothole can damage a tyre, wheel, lower arm, suspension bush, ball joint, track rod end, strut mount or wheel bearing and can also disturb wheel alignment.
Why did my car start knocking after tyre or wheel work?
A new knock after tyre or wheel work should be checked promptly. Wheel fittings, wheel seating, tyre clearance and anything disturbed during the work should be inspected before normal driving continues.
Is it safe to drive with a knocking noise when turning?
It depends on the cause. A light occasional noise may allow cautious driving to inspection, but avoid driving if the steering feels loose, the car pulls strongly, the knock is heavy or worsening, the wheel feels unstable or the noise began after an impact or recent wheel work.
When should I stop driving with a knocking noise?
Stop driving if knocking is accompanied by loose or unpredictable steering, severe vibration, strong pulling, obvious wheel movement, tyre damage, grinding, a heavy metallic clunk or concern that a wheel or suspension component is insecure.
Can a knocking noise when turning fail an MOT?
The noise itself is a symptom, but the underlying defect can affect the MOT if it involves excessive play, worn suspension or steering joints, damaged springs, insecure components, wheel-bearing play or unsafe wheel fittings.
How does a mechanic diagnose knocking when turning?
A mechanic reproduces the noise and compares steering angle, road speed, acceleration, braking and road bumps before inspecting CV boots and joints, wheel bearings, suspension bushes, ball joints, top mounts, track rod ends, steering components, brakes and wheel fittings.
How much does it cost to fix knocking when turning in the UK?
Repair cost depends on the fault. Anti-roll bar links and some bushes may be relatively inexpensive, while driveshafts, wheel bearings, suspension arms, struts or steering-rack repairs can cost several hundred pounds or more.
What is the best first check for knocking when turning?
First identify exactly when the knock occurs, such as full lock, gentle turns, acceleration, braking or bumps. Then check for obvious tyre or wheel damage, loose wheel fittings, CV-boot damage or grease before arranging a steering and suspension inspection.