2. Steering
Mechanical condition, steering wheel and column or handlebar, forks and yokes, steering play and electronic power steering (EPS) rules and inspection for car and passenger vehicle MOT tests.
In this section
- 2.1.1. Steering gear condition
- 2.1.2. Steering gear security
- 2.1.3. Steering linkage condition
- 2.1.4. Steering linkage operation
- 2.1.5. Power steering
2.1.1. Steering gear condition
To check the condition of the steering gear:
-
Put the vehicle over a pit or on a hoist and with the wheels resting on free moving turning plates – vehicles with a beam axle can be checked with the wheels raised above the ground.
-
Turn the steering from lock to lock and observe the operation of the steering gear.
Vehicles with a beam axle can alternatively be checked with the wheels raised above the ground.
If power steering is fitted, the engine must be running whilst turning the steering during these checks.
The use of turning plates is not mandatory for Class 5 vehicles but should be used if suitable plates are available.
| Defect | Category |
|---|---|
| (a) Excessive roughness in operation of steering | Major |
| (b) Sector shaft: (i) twisted or splines excessively worn (ii) twisted or splines worn to the extent that functionality is affected |
Major Dangerous |
| (c) Sector shaft: (i) excessively worn (ii) worn to the extent that functionality is affected |
Major Dangerous |
| (d) Sector shaft: (i) has excessive movement (ii) movement so excessive that functionality is affected |
Major Dangerous |
| (e) Steering box: (i) leaking oil (ii) leaking to the extent that oil is dripping |
Minor Major |
2.1.2. Steering gear security
‘Steering gear’ refers to any steering rack, box, idler, relay or intermediate drop arm pivot housing.
To check the security of the steering gear:
-
Put the vehicle over a pit or on a hoist.
-
Make sure the front road wheels are firmly on the ground.
-
Get an assistant to rock the steering wheel in both directions against the resistance of the ground or use wheel play detectors in rotational mode.
-
Visually check the security of the ‘steering gear’.
-
Check the strength and continuity of any load bearing structure within 30cm of any steering component mounting (a ‘prescribed area’).
For guidance on assessing corrosion and use of the corrosion assessment tool see Appendix A.
| Defect | Category |
|---|---|
| (a) Steering gear casing: (i) not properly attached (ii) retaining devices dangerously loose or relative movement to chassis/bodywork visible |
Major Dangerous |
| (b) Steering gear casing fixing holes in chassis: (i) elongated (ii) elongated to the extent that attachment is seriously affected |
Major Dangerous |
| (c) Steering gear fixing bolts: (i) missing or ineffective (ii) missing or ineffective to the extent that attachment is seriously affected |
Major Dangerous |
| (d) Steering gear casing: (i) fractured (ii) fractured and stability or attachment of casing affected |
Major Dangerous |
| (e) The strength or continuity of the load bearing structure within 30cm of any steering component mounting (a ‘prescribed area’): (i) is significantly reduced or inadequately repaired (ii) is so weakened that control of the vehicle is likely to be adversely affected |
Major Dangerous |
2.1.3. Steering linkage condition
To check the steering linkage condition:
-
Put the vehicle over a pit or on a hoist.
-
Make sure the front road wheels are firmly on the ground.
-
Get an assistant to rock the steering wheel in both directions against the resistance of the ground or use wheel play detectors in rotational mode.
-
Visually check the steering components for wear, fractures and security, including any rear wheel steering components.
If power steering is fitted, the engine must be running during the tests.
The presence and effectiveness of some locking devices, such as locking fluid or ‘nyloc’ nuts, cannot be easily determined. If you are not certain that a locking device is missing or ineffective, you should give the benefit of the doubt.
Relative movement due to excessive wear must be distinguished from relative movement due to built-in clearance or spring loading of a joint.
If rear wheel steering is fitted but is inoperative, check that the rear wheels are pointing straight ahead.
Unsafe modifications include:
- welded repairs
- the use of excessive heat to highly stressed components (see Appendix A)
- modifications likely to affect the roadworthiness of the vehicle
| Defect | Category |
|---|---|
| (a) A steering linkage component with: (i) relative movement between components which should be fixed (ii) excessive movement between components or likely to become detached |
Major Dangerous |
| (b) A steering ball joint: (i) with excessive wear or free play (ii) worn to the extent there is a serious risk of detachment |
Major Dangerous |
| (c) A steering linkage component: (i) fractured or deformed (ii) fractured or deformed to the extent that steering is affected |
Major Dangerous |
| (d) Steering linkage retaining or locking device missing or ineffective | Major |
| (e) Track rod or drag link ends seriously misaligned | Major |
| (f) A steering linkage component: (i) with an unsafe modification (ii) modified to the extent that steering is affected |
Major Dangerous |
| (g) Steering rack gaiter or ball joint dust cover: (i) damaged or deteriorated (ii) missing or no longer prevents the ingress of dirt etc. |
Minor Major |
| (h) Rear wheel steering inoperative and: (i) rear wheels not held in the substantially straight ahead position (ii) control of vehicle adversely affected |
Major Dangerous |
2.1.4. Steering linkage operation
To check the steering linkage operation:
-
Put the vehicle over a pit or on a hoist.
-
Put the wheels on free moving turning plates.
-
If the vehicle has power steering, turn on the engine.
-
Rotate the steering from lock to lock.
-
Check the steering linkage is not fouling any part of the vehicle.
-
If there’s a steering lock stop, check that it works.
A missing steering lock stop should only be failed if it was fitted as standard.
Vehicles with a beam axle can alternatively be checked with the wheels raised above the ground.
| Defect | Category |
|---|---|
| (a) Steering linkage fouling any part of the vehicle | Major |
| (b) Steering lock-stop missing or incorrectly adjusted | Major |
2.1.5. Power steering
If power steering is not working, you may have to do a road test to check if the steering is adversely affected.
Power steering fluid level should be checked through any sight glass, the cap should not be removed.
Power steering fluid leaks should only be rejected where a component, joint or seal has failed.
| Defect | Category |
|---|---|
| (a) Power steering fluid leaking or system malfunctioning | Major |
| (b) Power steering fluid: (i) level below minimum mark (ii) reservoir empty |
Minor Major |
| (c) Power steering: (i) inoperative (ii) inoperative and steering adversely affected |
Major Dangerous |
| (d) Power steering component: (i) fractured or insecure (ii) fractured or insecure and steering adversely affected |
Major Dangerous |
| (e) Power steering component: (i) fouling or misaligned (ii) fouling or misaligned and steering adversely affected |
Major Dangerous |
| (f) Power steering component: (i) with an unsafe modification (ii) modified and steering adversely affected |
Major Dangerous |
| (g) Power steering pipe, hose or wiring: (i) excessively damaged or corroded (ii) damaged or corroded and steering adversely affected |
Major Dangerous |
In this section
2.2.1. Steering wheel or handlebar condition
Before carrying out this inspection, make sure that any mechanism for adjusting the steering column is fully locked.
Exert only reasonable pressure on the steering wheel, particularly when the steering column is collapsible.
Push and pull the steering wheel or handlebar in line with the column or forks to check it’s properly secured.
| Defect | Category |
|---|---|
| (a) Relative movement between steering wheel and column: (i) indicating looseness (ii) such that there is a serious risk of detachment |
Major Dangerous |
| (b) Steering wheel: (i) retaining device missing (ii) likely to become detached |
Major Dangerous |
| (c) Steering wheel rim or spokes: (i) fractured or loose (ii) likely to become detached |
Major Dangerous |
| (d) Handlebar: (i) fractured or insecure (ii) fractured or insecure to the extent that steering is adversely affected or detachment likely |
Major Dangerous |
| (e) Handlebar: (i) excessively deformed or corroded (ii) deformed or corroded to the extent that steering is adversely affected or failure likely |
Major Dangerous |
| (f) Handlebar handgrips: (i) missing (ii) insecure to handlebar |
Major Dangerous |
2.2.2. Steering column or forks and yokes
Before carrying out this inspection, make sure that any mechanism for adjusting the steering column is fully locked. Exert only reasonable pressure on the steering wheel, particularly when the steering column is collapsible.
Some vehicles have flexible top bearings for the steering column which may have more than average movement.
Steering columns with universal joints or flexible couplings may show some movement which is not due to excessive wear or deterioration.
Unsafe modifications include:
- welded repairs
- the use of excessive heat to highly stressed components (see Appendix A)
- modifications likely to affect the roadworthiness of the vehicle
To check the steering column or forks and yokes:
-
Push and pull the steering wheel in line with column.
-
Push steering wheel or handlebar in various directions at right angles to the column or forks.
-
Check visually for play.
-
Check the condition of flexible couplings or universal joints.
| Defect | Category |
|---|---|
| (a) Excessive movement of centre of steering wheel up or down | Major |
| (b) Excessive radial movement between the top of the steering column and the shaft indicating an excessively worn top bearing | Major |
| (c) Excessive wear or play in a universal joint or a flexible coupling excessively deteriorated | Major |
| (d) Attachment of steering column: (i) defective (ii) defective to the extent that there is a serious risk of detachment |
Major Dangerous |
| (e) Unsafe modification to steering column, forks or fork yoke | Major |
| (f) Forks or fork yoke: (i) deformed, fractured or insecure (ii) in such a condition that steering control is adversely affected or detachment likely |
Major Dangerous |
| (g) Steering head bearings have excessive wear or play | Major |
To check steering play:
-
Make sure the road wheels are on the ground and pointing straight ahead.
-
Lightly turn the steering wheel left and right as far as possible without moving the road wheels.
-
Check the amount of free play at the rim of the steering wheel.
If power steering is fitted, the engine must be running.
Steering wheel free play should not be more than:
- 13mm for rack and pinion steering, or 48mm if there are several joints between the steering wheel and the rack
- 75mm for non-rack and pinion
These limits are for a standard 380mm diameter steering wheel. The limits should be adjusted up or down accordingly with larger or smaller diameter steering wheels.
Play due to wear or maladjustment must not be confused with apparent play due to the construction of the mechanism, such as caused by the deflection of flexible joints or spring compression in external power steering systems.
| Defect | Category |
|---|---|
| (a) Free play in the steering, measured at the rim of the steering wheel is: (i) excessive (ii) excessive to the extent that safe steering is affected |
Major Dangerous |
For the purpose of this inspection, electronic power steering includes any steering system that incorporates an electric motor to control or assist the steering.
If electronic power steering is an optional fitment on the vehicle but it’s been disconnected, the vehicle should only be failed if the steering is adversely affected. You may have to do a road test to check this.
If a vehicle has a manually switched electronic park assist but the power assistance is not working, the vehicle should only be failed if the steering is adversely affected. You may have to do a road test to check this.
For ‘fly by wire’ steering systems, check that the steered wheels are pointing straight ahead with the steering wheel in the straight-ahead position.
| Defect | Category |
|---|---|
| (a) EPS MIL indicating a system malfunction | Major |
| (b) On ‘fly by wire systems’, the angle of the steering wheel and the angle of the road wheels is: (i) inconsistent (ii) inconsistent to the extent that the steering is adversely affected |
Major Dangerous |
| (c) Electronic power assistance not working | Major |