Steering Wheel Play: MOT Requirements Explained

Understanding Steering Wheel Play in Your MOT Test

When it comes to your car's MOT test, steering is a critical component that ensures your vehicle can be controlled safely. One of the key checks performed by an MOT tester relates to the 'free play' in the steering system. This might sound a bit technical, but it's a straightforward concept that boils down to how much unwanted movement there is in your steering wheel before the road wheels begin to turn. This article will delve into the specifics of steering wheel play, what the legal limits are, and the common reasons why a steering wheel might fail its MOT.

The MOT test is designed to ensure that vehicles on the road are safe and meet minimum environmental standards. Steering is fundamental to vehicle safety. If your steering system has too much play, it can lead to delayed reactions, a loss of precise control, and potentially dangerous situations, especially at higher speeds or during emergency manoeuvres. Therefore, understanding the requirements for your steering wheel is vital for any vehicle owner.

What is 'Free Play' in Steering?

'Free play' in a steering system refers to the amount of rotational movement in the steering wheel that does not result in any corresponding movement of the road wheels. Essentially, it's the 'slack' or 'give' in the system. In a perfectly tuned steering system, the moment you turn the steering wheel, the road wheels should react immediately and proportionally. Any delay or looseness before the wheels respond is considered free play.

Several factors can contribute to free play:

• Worn Steering Column Bearings: The bearings that support the steering column can wear over time, leading to excessive movement at the top of the column.
• Loose Steering Wheel: The connection between the steering wheel and the steering shaft needs to be secure. If it's loose, the wheel can turn slightly before engaging the shaft.
• Wear in Universal Joints or Flexible Couplings: These components connect different parts of the steering column and can develop wear, introducing play.
• Wear in the Steering Rack or Box: For vehicles with rack and pinion steering or traditional steering boxes, internal wear can create significant play.
• Loose Track Rod Ends or Ball Joints: These connect the steering rack to the wheels and can wear, contributing to play.

MOT Requirements for Steering Wheel Play

The MOT manual provides specific guidelines for the acceptable amount of free play. These limits are in place to ensure a reasonable level of responsiveness from the steering system.

According to the provided MOT checklist:

• Non-rack and pinion steering: A maximum of 75mm of free play is allowed. This typically applies to older vehicles with steering boxes.
• Rack and pinion steering: A maximum of 13mm of free play is allowed. This is a much tighter tolerance, reflecting the more direct nature of this steering system.
• Multiple Joints: Where there are several joints between the steering wheel and the rack, up to 48mm of play may be accepted on a 380mm diameter wheel. This acknowledges that more joints can naturally introduce a small amount of cumulative play.

It's important to note that these measurements are typically taken at the steering wheel itself. The tester will turn the wheel back and forth to gauge the amount of movement before the road wheels begin to respond.

Reasons for Steering Wheel Failure in the MOT

Beyond just excessive free play, several other issues with the steering wheel and column can cause a vehicle to fail its MOT:

1. Steering Wheel Condition:
   • Weakened by Modification: Any modifications that compromise the structural integrity of the steering wheel can lead to failure.
   • Cracks or Fractures: Significant cracks or fractures in the steering wheel itself, especially if they could impair control or injure the driver's hands, are a reason for rejection. However, minor cracks or damage to the covering skin or hub are generally not a failure point.
   • Improper Control: If the condition of the steering wheel is such that it hampers proper control of the vehicle, it will fail.
2. Steering Column and Shaft Issues:
   • Adjustable Column Not Locking: If your vehicle has an adjustable steering column, it must be able to lock securely in a fixed position.
   • Movement Between Shaft and Wheel: Any looseness or play directly between the steering shaft and the steering wheel itself is a failure.
   • Excessive Radial Movement (Play) at Column Top: Significant side-to-side (radial) play at the top of the steering column indicates worn upper bearings, which is a common failure point. Note: some vehicles have flexible top bearings, and more movement may be acceptable in these cases.
   • Insecurity at Top Mounting Bracket: The bracket securing the steering column to the vehicle's structure must be secure.
   • Excessive Steering Shaft End Float: This refers to fore-and-aft movement of the steering shaft, indicating worn bearings or other internal issues.
3. Couplings and Joints:
   • Insecurity, Excessive Play, or Deterioration: Any flexible couplings or universal joints in the steering system that are loose, worn, or showing signs of deterioration will cause a failure.
4. Securing Devices:
   • Missing or Insecure Retaining/Locking Devices: Split pins, locking nuts, or other devices used to secure steering components must be present and properly fitted.

The MOT Steering Check: What the Tester Does

An MOT tester will perform a series of checks to assess the condition and play within your steering system. These checks are thorough and cover various aspects:

• Inside the Car Checks:
  • The tester will first inspect the condition of the steering wheel itself for any obvious damage or modifications.
  • They will check that the steering wheel is securely attached to the steering shaft.
  • The steering column's upper bearings are inspected for wear by applying pressure to the wheel.
  • The tester will check for excessive end float in the steering shaft.
  • Clamping bolts, split pins, and locking nuts related to the steering column are checked for security.
  • Crucially, the tester will measure the 'free play' in the steering wheel as described above.
  • All flexible couplings and universal joints are checked for wear and security.
• Under Bonnet Checks:
  • The security of the steering rack or steering box and its mountings are inspected.
  • Play in any steering joints accessible from under the bonnet is checked.
  • Other swivel joints within the steering system are also inspected if they are readily visible.
• Under Vehicle Checks:
  • With the vehicle stationary, the tester will turn the steering wheel from lock to lock while observing and feeling the steering joints for excessive play or wear.
  • If the vehicle has power steering, this system is checked with the engine running.
  • The security of the steering rack or box attachment to the chassis is verified, checking for tight nuts and bolts, and any structural cracking or corrosion around the mounting points.
  • The wheels are turned from lock to lock while the vehicle is on swivel plates to ensure they don't foul the vehicle's structure or brake lines.
  • When the wheels are jacked up, wheel bearings are checked for play.
  • Steering rack gaiters and front outer constant velocity (CV) joint boots are examined for damage or leaks.
  • Metal and rubber bushes, split pins, and locking devices within the suspension and steering are checked for condition and security.
  • For vehicles with rear-wheel steering, this system is also checked from underneath.

Table: Steering Play Limits Comparison

Frequently Asked Questions (FAQs)

Q1: What is the most common reason for a steering wheel to fail an MOT?
A1: The most common reasons are excessive 'free play' in the steering system, worn steering column bearings, or loose steering joints.

Q2: My steering wheel has a small crack on the cover. Will it fail?
A2: Generally, minor cracks or damage to the covering skin or hub of the steering wheel are not reasons for rejection, provided the structural integrity is not compromised and it doesn't pose a risk to the driver's hands.

Q3: My steering feels a bit loose, but I'm not sure if it's too much for the MOT. What should I do?
A3: It's best to have your steering system checked by a qualified mechanic before your MOT. They can identify any potential issues, such as worn components or excessive play, and advise on necessary repairs.

Q4: What is 'end float' in the steering shaft?
A4: End float refers to the fore-and-aft movement of the steering shaft within its bearings. Excessive end float indicates wear in the bearings and will cause the vehicle to fail the MOT.

Q5: Does the type of steering wheel material affect the MOT test?
A5: The MOT primarily focuses on the condition, security, and functionality of the steering wheel and system, not the material itself, unless the material is damaged or modified in a way that compromises safety.

Conclusion

Maintaining your vehicle's steering system is paramount for safety and compliance with MOT regulations. Understanding the concept of 'free play' and the specific limits set by the MOT test will help you anticipate potential issues. Regular checks and prompt repairs of any wear or damage in the steering column, joints, or steering rack will not only help your vehicle pass its MOT but also ensure a safer driving experience for you and other road users. Don't overlook the importance of a responsive and secure steering system – it's your primary connection to the road.

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