Collapsing suspension due to coil spring failure seems to be a growing problem – caused by a combination of recent harsh winter conditions and weight-saving designs.
AA patrols have reported a big increase in the number of broken coil springs – in the year to February 2011 we saw more than 21,000 breakdowns related to spring failure. The number of broken springs in January 2011 was 25% higher than in January 2010. Figures from 2012 show no signs of the problem going away.
On older cars with fairly small diameter and narrow wheels, the damage was usually confined to the spring itself when one broke.
Modern cars are fitted with much bigger/wider wheels for better looks and handling but the penalty is that the tyre side-wall is much closer to corrosion.
Most often coil spring failure seems to be caused by corrosion, accelerated by salt applied to the roads in winter.
The corrosion exposes the micro structure of the material to the atmosphere and makes it susceptible to a process known as hydrogen embrittlement of the spring. If a spring breaks, tyre damage is much more likely.
During winter and early spring, a regular clean underneath the car with a hose or pressure washer may help extend spring life.
A common symptom of worn ball joints is uneven tyre wear. This occurs when the suspension and wheels are misaligned, leading to the tyres not meeting the road properly.
Instead of being centred with the weight of the tyres in the middle of the tyre, the tyres wear on the edges or possibly the centre of the tyre. This is clearly visible because the tread of the tyres will be worn down at a greater rate at certain points of the tyre than others. In some cases, the tyres will be worn to the point that the threads will stick out.
The most common pattern of tyre wear associated with a defective ball joint is camber wear. This is tyre wear that is specific to one side of the tyre because of the suspension being uneven.
One of the most dangerous conditions that could occur from worn ball joints is problems with steering.
If a ball joint is worn or damaged, it will not allow the steering mechanism to fluidly turn the wheels in response to the driver. This can make steering difficult and make driving the car dangerous especially if the driver needs to take sudden, evasive action.
A worn ball joint can make the steering feel either too loose or too tight depending on how the ball joint and socket are wearing. If the ball joint and socket are wearing out together, the ball joint will become smaller while the size of gap in the socket will increase. This will increase the tolerance in the joint and make steering feel loose or sloppy.
However, a worn ball joint can also cause tight steering, making it hard to turn the car quickly and feel like the car is losing power steering.
A ball joint will make loud noises as it begins to wear. These noises can start as minor clicks that are felt in the steering wheel, but gradually increase to loud thumps and clunks as the damage to the ball joint gets worse.
The noise can be especially noticeable when the weight of the car shifts to and from the wheel with the bad ball joint, such as when the car drives over a pothole.