What is wrong with the steering rack

Many drivers have heard of the steering wheel angle sensor or steering wheel position sensor. However, few people realize the full significance of this control element. Do you know that the operation of the entire electric power steering depends on the condition of the sensor?

Steering rack failures

Leakage

Hydraulic power steering units are equipped with high-pressure seals that keep the oil inside the steering rack and protect it from leaks. Rubber and Teflon seals are also used in hydraulic power steering systems to ensure proper oil circulation. Sealing elements are made of durable and wear-resistant materials such as oil-resistant rubber, Teflon, and metal alloys.

Unfortunately, there are no materials invented yet that are eternal, so all parts wear out over time and lose their properties. One of the most common faults in steering racks is oil leakage.
Steering wheel angle sensor - electric power steering component that determines the position of the steering wheel within a range of 720 degrees in each direction. The sensor is most often installed on the electric column under the steering wheel, less frequently on the pinion.

One of the most common faults in steering racks is oil leakage.

Why does hydraulic power steering leak:

• Oil seals of the distributor and hydraulic actuator are worn due to normal mechanical wear. Moving parts of the steering rack (rack body, rack bar, pinion) rub against oil seals, gradually wearing them out.
• Parts of the steering rack corrode when shields are worn out and moisture penetrates the device. Rust on the piston and pinion accelerates the wear of oil seals and causes rapid leakage.
• O-rings and seals lose their shape and physical properties over time due to constant pressure, oil, and high temperatures, causing the steering rack to leak.
• As a result of the breakdown of the bearing in the distributor or wear of the bushings.

If there are oil stains under the car, the hydraulic oil tank level constantly drops, and the wheels respond to steering with a delay, check the condition of the steering rack. These symptoms may also indicate leaks in the power steering pump, hoses, and tank. Therefore, exercise caution during inspection and do not forget to check other components of the steering system.
A decrease in the level in the hydraulic oil tank is an obvious reason to check the steering rack.

In the case of steering rack leaks, air enters the system, causing additional load on the pump. If there is a lack of oil, and the system is clogged, the power steering pump will make noise, the steering system will become heavy, and the driving comfort will deteriorate.

To prevent leaks from the steering rack, it is sufficient to regularly check the condition of the shields, inspect the device for corrosion, replace sealing elements in a timely manner, and regularly service it.

Knocking and play

Drivers often complain about knocking around the front axle. Knocking is often accompanied by play in the steering wheel, which is particularly noticeable when driving on bumpy roads. In most cases, the faulty steering rack is to blame. Knocks and play can occur in any steering rack, regardless of its design and type.

Improper adjustment of the steering rack

Improperly adjusted steering racks usually knock, as do units with a worn side mount for the gear rack. In such cases, the rack and worm shaft of the distributor collide with each other, and the teeth of the shafts are damaged.

If the position of the gear rack is misadjusted, in addition to the knocking noise, the driver will feel characteristic vibrations in the steering wheel. If the vehicle is equipped with a mechanical steering rack, there will be no other signs of incorrect adjustment.

In power steering racks, a loose rack bar causes improper operation of other system elements.

In hydraulic steering racks, a faulty distributor mechanism wears out oil seals and causes leaks.

In the case of an electric unit, knocking and loose parts of the unit gradually damage the components of the electric drive system, affecting the position and operation of sensors. This malfunction will have a significant impact on the vehicle's steering; for example, the steering wheel may become stiff, turn spontaneously, sway, or not return to the center position.

In this case, it is worth entrusting the inspection and adjustment of the steering rack to a service center to eliminate vibrations and knocking. Careful and cautious driving will help avoid knocking and play in the device.

Worn lateral thrust

Worn lateral thrust is another cause of knocking and play, consisting of several elements. What fails in the lateral thrust:

• The foil insert is worn out. It is a plastic insert mounted on the thrust piston. The foil insert protects the rack bar from excessive friction against the metal thrust piston. A worn insert will cause the thrust piston to shake and wear out quickly.
• The spring in the lateral thrust is cracked or corroded. The spring will gradually wear out and lose its physical properties. The more aggressively you drive, the faster the spring will wear out.
• Corroded and jammed lock nut prevents adjustment of the position of the rack bar.

If there is a problem with the spring, replace the worn part or the entire unit. Prevention in this case is simple: drive carefully, take care of the vehicle, and perform timely inspections.

Worn pinion bearings

Another reason for knocking and play is worn pinion bearings. Bearings are not eternal either – they "age," deteriorate due to mechanical friction, rust on the pinion, and careless driving on uneven roads. To eliminate the problem, the worn bearing needs to be replaced, and the condition of the remaining pinion components should be checked for damage and corrosion.

Some drivers forget or are unaware of the existence of a dust seal that covers the pinion from above and protects it from rust and contaminants. It is worth periodically checking its condition – this protective element performs the same function as the steering rack cover.

Wear of the support bushings

The rack bar also knocks if the bushings are worn. More precisely, it is not the bushing but the steering rack elements that are out of place. A steering rack with worn bushings will knock but will not have vibrations and play in the steering wheel. The causes of bushing wear are standard: mechanical wear, corrosion on the shaft, sudden shocks, and vibrations during driving.

Attention! Knocking at the front axle may also be caused by faulty tie rods and tie rod ends. Shock absorber struts can also knock in these cases. However, in these cases, you will not feel any vibrations in the steering wheel. If there is knocking but the steering rack is in order, check the chassis – it may be causing the problem.

Cracking during turning

Unpleasant creaking sound in the front axle area when turning the steering wheel is a clear sign of corroded steering rack elements. The following parts may creak:

• Pinion bearings;
• Torsion and pinion mounting point on the steering column;
• Worm shaft and rack bar

Now you know what causes pinion bearing wear.

Rust and wear on the teeth of the worm and rack bar

Rust on the teeth of the worm and rack is a common problem with steering racks whose owners do not care about the condition of the dust seal. In a situation where it breaks, moisture enters the device, causing corrosion.

First of all, corrosion spreads to the central shafts of the mechanisms. The reason is simple – most of the time, the car is driven in a straight line, so the lubricating oil does not reach the pinion. When turning, the pinion rubs against theracks, causing rust.

When the steering rack is clogged, the pinion and worm shaft grind the rust, making a characteristic creaking sound. If you hear it, carefully disassemble the steering rack and clean the parts from rust.

Rust on the teeth accelerates wear of the pinion bearings. In the worst case, the teeth may wear out unevenly, which will cause knocking during driving.

Irregular wear of the teeth

Irregular wear of the teeth is another problem caused by rust. In this case, it is not enough to clean the rack bar and pinion from rust – you need to adjust the axial gap of the pinion and rack bar.

This procedure requires removing the pinion and rack bar  and adjusting the gap between them using special tools. Unfortunately, not every driver can cope with such a task on their own, so if there are irregularities in the operation of the steering rack, it is better to contact a service center for help.

Vibrations during driving

If the steering wheel vibrates while driving, the distributor bearings are most likely worn out. Bearings are the weakest link in the power steering, as they wear out quickly and lose their properties. When the bearings wear out, the distributor and the entire steering system begin to vibrate.

It is almost impossible to determine the worn bearing by external signs – no oil stains or broken parts are visible. The only way to detect a problem is to disassemble the gearbox and check the condition of the bearing. If the bearing is cracked or jammed, replace it with a new one, and the vibrations will disappear.

Clogging of the rack bar

In some cases, the distributor bearings remain intact, but the steering wheel begins to vibrate. This happens if the rack bar of the worm is clogged with dirt and rust.

The rack bar requires constant lubrication, and the oil is supplied through small holes. When driving on dirty roads, the pinion is clogged, the rack bar does not receive enough oil, and the steering rack start to vibrate.

If the pinion is clogged, do not disassemble the steering rack – remove the pinion, clean it, and reinstall it in place. This will be enough to eliminate the vibrations and restore the normal operation of the power steering.

Steering Rack Diagnostics

Diagnostics of the steering rack involves several stages, which are performed sequentially.

Checking the steering wheel for play

First, the mechanic checks the condition of the steering wheel. To do this, the driver must sit in the driver's seat, start the engine, and turn the steering wheel from side to side.
If the wheel has free play, the steering rack needs adjustment. The mechanic can do this by adjusting the position of the rack bar. If the rack bar is not adjustable, the mechanic will replace it.

Checking the steering wheel for play

If there is no free play in the steering wheel, the mechanic will check the condition of the steering rack with the engine off. To do this, the mechanic will manually turn the steering wheel and check for any resistance, knocks, and roughness in the movement.

If the steering rack is okay, the steering wheel will turn smoothly, without any resistance and extraneous sounds. If there are knocks, the rack bar may be worn out, thepinion bearings are faulty, or the lateral thrust is damaged.

Checking the steering rack with the engine running

The next stage of diagnosis is checking the steering rack with the engine running. The mechanic will start the engine, turn the steering wheel, and listen to the sounds coming from the front axle.

If there is a creaking sound, the pinion, worm shaft, and rack bar may be corroded. If there are knocks and vibrations, the lateral thrust andpinion bearings are faulty.

Checking the hydraulic system

The last stage of the diagnosis is checking the condition of the hydraulic system. To do this, the mechanic will turn the steering wheel to the maximum angle, lock it in this position, and inspect the steering rack and hoses for leaks.

If there are leaks, the oil seals of the hydraulic actuator,pinion, or hydraulic hoses are faulty. In this case, the mechanic will replace the seals or hoses.

Checking the hydraulic system

After completing all the diagnostic procedures, the mechanic will determine the cause of the steering rack malfunction and take appropriate measures to eliminate it.

Summary

The power steering is an important component of the vehicle, ensuring the driver's comfort and safety. The main elements of the power steering are the hydraulic pump, steering rack, and hydraulic actuator. The steering rack is responsible for converting the rotary motion of the steering wheel into the linear motion of therack bar.

There are several types of steering racks, including mechanical, hydraulic, and electric. Each type has its advantages and disadvantages. Mechanical steering racks are simple and reliable but have a heavy steering wheel. Hydraulic steering racks provide a more comfortable and smoother ride but require regular maintenance. Electricsteering racks are modern and efficient but are more expensive and complex.

Common steering rack problems include oil leakage, knocking, play in the steering wheel, creaking during turning, uneven wear of teeth, vibrations during driving, and corrosion of rack elements. These problems can be caused by various factors, including wear and tear, lack of maintenance, and driving conditions.

Diagnostics of the steering rack involves checking the steering wheel for play, testing the steering rack with the engine off, checking the steering rack with the engine running, and inspecting the hydraulic system. Once the cause of the steering rack malfunction is identified, appropriate measures can be taken to repair or replace the faulty components.

Regular maintenance, careful driving, and timely repairs are essential to ensure the proper functioning of the steering rack and, consequently, the overall safety and performance of the vehicle. If you experience any problems with your steering rack, it is recommended to consult with a qualified mechanic or visit a service center for a thorough inspection and necessary repairs.