How Steering Parts Affect Steering Noise
Most steering noises are not random, and the sound often points to a specific component or a specific problem.
Knocking Over Bumps
If you hear a knocking sound as you drive over bumps in the road then it could be your track rod ends. These are small parts that connect the steering rack to the wheel hubs and have ball joints. These joints can wear over time and cause the ends to become loose. This in turn can cause problems when steering and so should be checked as soon as possible.
Clunking on Full Lock
Clunking on Full Lock: A worn or tired steering column universal joint, or a worn steering rack can also cause a clunking sound on full lock. A good steering specialist will be able to check for any movement in the steering column, and also check the rack for any wear. If the rack is worn it will usually need to be replaced.
Whining That Changes With Engine Speed
A whining sound which varies with engine speed (i.e. not road speed) could indicate that the power steering pump is failing. The power steering pump is driven by the engine and therefore its noise is typically varied with engine speed. Power steering components can deteriorate gradually and it is wise to investigate and potentially replace a component of this nature before it actually fails.
Squealing on Full Lock
Squealing: A squealing noise can occur when turning at full lock. This can be due to low power steering fluid or worn power steering pump components. The easiest thing to check first is the level of fluid in the power steering system. If the level is low then topping up the fluid is a simple task that can be done to rectify the problem. However, if the fluid level is OK then worn steering components could be the cause. Worn or failing steering components, even with sufficient fluid, can create a road risk. This is covered in more detail by the RAC Foundation in relation to steering and suspension faults and vehicle safety.
Grinding When Turning
A grinding sound whilst turning indicates that either the CV joints on your drives have worn, or that there are damaged rack ends within the steering rack. These are two parts that can fail and will need a full inspection prior to potentially expensive repair.
Listen out for these sounds and have your car serviced before they become major problems.