Suspension arms, bushes and ball joints are replaced in the workshop every day. Every time a vehicle’s wheel moves up or down, and when the steering wheel is turned, these components are in use and as a result, start to wear. These components are used to connect the wheel to the chassis and suspension components, like the coil or leaf springs.

Suspension arms need to allow up and down movement of the wheel but still hold the wheel central inside the wheel arch (not allowing forward and backwards movement). So, they need to be strong, but pivot both ends. To allow the arm to pivot, ball joints and/or bushes are used.

Ball joints wear because of constant use and leads to excessive movement in the suspension components. This will lead to a rattle or knocking noise within the cabin.
Bushes also knock when perished, worn or become unbonded from their housing. They commonly fail the MOT due to excessive wear or free play which, if not rectified promptly, can cause uneven tyre wear and handling issues.

Like CV Joints, Ball joints have a rubber boot covering them to retain the lubricating grease. If this boot is split, damaged or insecure, they can fail the MOT.

Common Mot Failures

• Excessive movement and free play
• Ball joint boot split
• Bushes perished, split or worn

 
The reason these are considered an MOT failure is because the vehicle’s handling can be seriously affected and cause the car to pull left or right. So, it is vital to keep the suspension in good working order.

In addition, premature and uneven tyre wear are caused by play in the suspension and steering joints. Whenever a steering or suspension joint is replaced, the alignment must be checked/adjusted.
 
Some vehicles, particularly larger German manufactured ones, have several suspension arms on each wheel. They may fail on upper, lower, upper rear most etc. 

CV joints, boots (gaiters) and driveshafts are a common MOT failure. All drive-shafts and prop-shafts have a flexible joint at either end which needs continuous lubrication. These joints (CV joints) have a rubber boot to hold the grease within the joint itself. These split over time and allow the grease to escape. This is an MOT failure due to grease escaping causing premature wear of the CV joints, and in some cases, can spray grease onto your vehicle brake components.

• CV stands for Constant Velocity
• Most common failure is the boots splitting allowing grease to escape
• Drive-shafts link the transmission to the wheels
• Prop-shafts link the transmission to the differentials

 
Common MOT Failures

• The CV boot splits
• The CV joints wear and have free play – usually as a result of the boot splitting
• The CV boot retaining clips brake causing the boot to become insecure.

​Mark has been included on the IMI TechSafe Register, ensuring the highest standards of workmanship and safety when working on electrified vehicles. The Institute of the Motor Industry’s (IMI) TechSafe standards for car technicians has been officially endorsed by the Government’s Office for Low Emissions (OLEV).
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EV owners can search the IMI Professional Register to check technician competency levels at their local garage and is a crucial step in providing confidence that their vehicle can be serviced, maintained and repaired by their local garage with the right skills and qualifications. We are pleased to say that Mark is a registered TechSafe Technician and that all our technicians are trained to meet the required safety standards for working on electrified vehicles. Call us if you would like more information regarding any of our services -  01823 617790