Steering system reconditioning

Steering gear is a precise, safety-critical part of the car. After 2000, manufacturers began to equip hydraulic power steering systems with electrical systems, with the aim of eventually replacing hydraulic systems completely with electronic modules.

Due to its complex construction and diversification of functions, the cost of a brand new transmission often reaches the value of the vehicle in which it is to be replaced. For this reason, a professional repair guarantees safety, but also brings financial benefits.

The advent of power steering systems equipped with electronic servos was a major step in the evolution of passenger car steering systems. As more and more components, functions and technologies were incorporated into modern steering gears, they became more complex and vulnerable compared to hydraulic systems.

The professional reconditioning of such a critical part of the vehicle requires the right knowledge and technology. Modern diagnostic equipment simulates the operating conditions of the transmission on the vehicle, confirming the correctness of the repair. Developed procedures guarantee, above all, high quality and operational safety. For this reason, it is worthwhile to have the power steering system repaired by a company that meets all the above conditions, such as Turbo-Tec.

Since the beginning of 2016, Turbo-Tec, a company well known for the remanufacturing of turbochargers and diesel injection systems, has started remanufacturing hydraulic and electric power steering systems. The steering systems are repaired using the highest quality parts, guaranteeing trouble-free operation in the long term.

The steering gears repaired at Turbo-Tec differ from those of other companies in that, after the repair, the steering gear is fitted with brand-new steering rods and covers, which guarantees quick installation on the vehicle, facilitates correct alignment and gives the vehicle owner the assurance that the repair and replacement of the steering gear has been carried out in accordance with the vehicle manufacturer's technology.

The immobilisation time of the car is reduced to a minimum, while maintaining the highest quality, which is confirmed by a two-year guarantee.

Let's find out what technical solutions we can find in passenger cars and which steering systems can be repaired?

Hydraulic assistance

Until around 2005, the most popular gearboxes operated with a fully hydraulic servo system. In this arrangement, the pump was driven by the engine via the accessory belt. Hydraulic fluid from the pump was directed at high pressure to the steering gear, assisting in wheel deflection. This type had the lowest failure rate. The power of the power steering was dependent on the speed of the vehicle and was regulated mechanically by mechanically varying the capacity of the hydraulic pump or controlled by an electro-valve.

Given the current age of vehicles equipped with the above solution, their mileage and operating conditions, a number of components can be potential sources of failure, ranging from wear and tear on sealing components and internal mechanical components to corrosion damage.

Turbo-Tec offers a comprehensive repair service for hydraulic steering gears and their associated pumps.

Electro-Hydraulic Steering System /EHPS/.

In fully hydraulic systems driven by the accessory belt, the power steering pump is always pumping oil, even when there is no need for it. To minimise power loss and precisely regulate the pump's output, an electric motor is used to drive the pump.

The fluid pressure and pump output, i.e. the force with which the steering is assisted, can be precisely adjusted depending on the driving parameters at the time. The pump motor operates at a maximum speed of around 10,000 rpm when the steering wheel is turned quickly at low speeds, e.g. manoeuvring in a car park. If the vehicle is not moving and there is no steering wheel rotation, the pump operates at around 2,000 rpm while constantly being ready to increase its speed. If the vehicle is moving at high speed and the steering wheel movements are negligible, the electric motor does not run. The lack of constant drive from the combustion engine saves up to 75% of energy. The pump has an integrated controller in which its operating characteristics are stored, tailored to the characteristics of the vehicle in question. The pump also has an integrated reservoir for the power steering fluid. Regulation of the power steering is carried out on the basis of basic information provided by the relevant sensors:

vehicle speeds,
steering wheel turning speed,
engine speed.

Fully electric power steering /EPS- Electric Power Steering/

The benefits of electric motors, their efficient operation and the possibility of precise control, have resulted in the gradual phasing out of hydraulic systems in passenger cars. Electric power steering systems are already fitted to every second vehicle.

Electrically assisted systems are completely devoid of any hydraulic component. The appropriate assisting torque at any given time is generated by the movement of an electric motor mounted on the steering column (EPSc systems) or directly on a gearbox (EPSr) with different power transmission variants (rack-and-pinion, belt, ball).

The input signals in EPS systems are extended compared to electro-hydraulic systems and include the following:

steering angle sensor /on the steering column or in the gearbox/
torque /torsion bar torsion sensor/
Angle speed and rev/minute sensor for electric motor
electric motor temperature sensor
power supply
engine speed
vehicle speed
ESP intervention

A larger number of sensors and input signals also means a greater number of opportunities for potential errors, so the steering self-diagnosis system is also extensive. The most common errors are failure of the torque or steering angle sensors. These two sensors are integrated into a single module on some models.

The reconditioning process includes not only the replacement of these sensors, but also the diagnosis of all transmission components for possible damage. Damaged components are replaced with new ones.