Understanding exactly how it is arranged steering-railIt is a fundamental skill for any auto mechanic or car owner looking to self-maintain their machinery. Without visualization of internal processes, it is impossible to qualitatively diagnose knocks, backlashes or leaks of working fluid. Schematic image turns a complex mechanism into a clear map, where each element has its own specific place and function.
In modern cars, especially equipped with a system Electro-Hydraulic Power Steering (EHPS) or an all-electric amplifier, ignoring the electrical part of the circuit can lead to erroneous conclusions when repairing. The mechanical part is responsible for transmitting force, but the electronics dictate the nature of this effort. Therefore, when starting to disassemble or order a remplekt, it is necessary to clearly represent the interaction of all components.
In this article, we will take a detailed look at the mechanism, go through the main nodes and identify typical problems that can be diagnosed by simply looking at the drawing. You will learn to distinguish the design features of different types of slats and understand why some parts fail more often than others. This knowledge will save you money on unnecessary parts and time in service.
General structure and operating principle of the mechanism
The classic steering slat scheme is a converter of the rotational movement of the steering wheel shaft into the translational movement of thrusts that turn the wheels. The main element here is the gear, where the gear connected to the steering shaft, enters into engagement with the rack. It is the quality of this engagement that determines the sharpness of steering and the presence of backlashes.
Depending on the type of amplifier, hydraulic pistons or an electric motor are added to the mechanical part. In hydraulic systems slug-hooter is a key node that directs the pressure of oil into the desired cavity of the cylinder when turning the steering wheel. If on the diagram you see a complex block of valves and a torsion, then before you a classic GUR, requiring special attention to the purity of the liquid.
Electrical circuits look different: here the motor can be located on the shaft, on the ram body or be integrated into the gear. Servo drive receives signals from angle of rotation and speed sensors, creating the necessary force. Understanding the location of the motor on the circuit is critical, since its replacement often requires removing the entire assembly, which is time-consuming.
⚠️ Attention: When studying the scheme, pay special attention to the direction of the flow of working fluid (arrows). The erroneous connection of the hoses "feed" and "reverse" can instantly disable the glands and pump GUR.
When looking for a circuit for your car, always use a VIN code, since even within the same model, the manufacturer can change the suppliers of steering mechanisms (ZF, TRW, Koyo), and their designs will differ.
Key elements of the steering rack scheme
A detailed study of the drawing allows you to identify several critically important nodes, the condition of which depends on the safety of driving. First one goes. crankcase The main body, inside which the rake moves. It should be perfectly sealed, as high pressure is created inside (up to 100-150 bar in GUR systems).
The second most important element is sealer and gums. On the scheme, they are indicated by special hatchings or takeaways. Their task is to prevent oil from flowing between the chambers and leaking out. Wear of these elements is the most common cause of malfunctions, leading to the appearance of backlashes and leaks.
The third component is pole-holder (support bushing) He presses the rack to the gear, picking out the gaps. Adjustment of the paddle often allows you to eliminate knocking without a complete bulkhead of the knot, if the wear of the teeth is not yet critical. In the diagrams, this node is usually shown with a adjusting screw or spring.
- 🔧 The golden mechanism: controls fluid flows, reacting to the rotation of the torsion; sensitive to pollution.
- 🔧 Entrance shaft: transmits torque from the steering column, often has a cross or cardannacle.
- 🔧 Steering rods and tips: They transmit the force to the rotating fists, have hinged joints.
- 🔧 Sensors (for EUR/EHPS): read the angle of rotation and speed, transmitting data to the control unit.
Each of these elements in the diagram has its own index. When ordering spare parts, it is important not to confuse, for example, the oal shaft and the oal rod, as they can have different designs and sizes. Visualization helps to avoid errors in the assembly.
Differences in hydraulic and electrical circuits
The main difference lies in the source of the effort created. In a hydraulic rail, there is always a pump (usually driven by a belt from the engine), a tank with liquid and high/low pressure highways on the circuit. The mechanical part here serves only as a guide for the hydraulic piston, which pushes the rail.
In the electrical variants (EPS) the circuit is simpler in terms of hydraulics (it does not exist), but more complex in terms of electronics. Here you will see the control unit, torque sensor and electric motor. The motor can turn the shaft (scheme) Column Assist) or the rack itself through the screw gear (scheme) Direct Drive).
Why are electrical circuits more expensive to repair?
In electric slats, it is often impossible to replace individual components (sensors, motor) without special equipment for calibration. While hydraulic rails can often be re-sized in garage conditions, electric rails require software adaptation after replacement of nodes.
Electrohydraulic systems (EHPS) combine both approaches: the pump is electric and only switches on when necessary, which saves fuel. On the circuit, it looks like a hydraulic rail, but with a separate electric pump often carried out into the under-hood space.
| Characteristics | Hydraulic (GUR) | Electrical (ERM) | Electrohydraulic (EHPS) |
|---|---|---|---|
| Source of effort | Engine pump | Electric motor | Electron pump |
| Dependence on ICE | High (power takes away) | Absent. | Low (current only) |
| Sensitivity to water | Low (closed circuit) | High (contact corrosion) | Medium |
| Typical malfunction | Glue leak, wear and tear of the pair | Sensor failure, motor failure. | Pump failure, leakage |
Understanding these differences helps you find the root of the problem more quickly. If there are no hydraulic lines on the circuit, it is pointless to look for oil leakage, and vice versa, the absence of electrical connectors indicates a purely mechanical or hydraulic nature of the assembly.
Typical faults in the drawing
By analyzing the circuit, you can predict where exactly the problem will occur. Zone shaft from the body is a place of constant friction and high pressure. Here, the glands most often wear out, which leads to the appearance of oil on asphalt or on anthers.
The central part of the reiki, where the teeth are engaged, is subject to shock loads. On the schemes of worn nodes, it is often seen how the tooth profile changes or the production appears at the point of contact with the patio. This causes a characteristic knock when passing irregularities.
⚠️ Attention: If you see a system of “variable” step of teeth (different pitch in the center and at the edges), remember that such a rake requires precision adjustment. Any error in assembly will result in uneven steering effort.
In electrical circuits, the weak point is torque-prooflocated on the entrance shaft. It is very sensitive to vibrations and moisture. Its failure leads to the loss of the amplifier or its uncontrolled operation, which is dangerous.
☑️ Diagnostics by circuit
Disassembly and assembly procedure according to the scheme
You should always start with a study. numbering details on the explosion circuit. This helps to understand the sequence of removing elements. Usually the process begins with the removal of the steering rods, then the protective casing is removed, after which access to the insides is opened.
When disassembling the hydraulic part, it is critically important to maintain cleanliness. The hit of one grain of sand in the spool mechanism can lead to a jamming of the reiki on the move. All rubber seals during assembly are necessarily lubricated with a special lubricant compatible with the liquid GUR.
Electrical slat assembly often requires calibration of the “zero position” of the sensors. Without this, the car can “pull” to the side or the amplifier will not work properly. The connection circuit of the connectors must be observed with accuracy to the contact.
Sequence of action:1. Remove the steering tips.
2. Disconnect the steering shaft card.
3. Dismant the rack from the subframe.
4. Remove the anthers and tractions.
5. Disassemble the body (only if you have a remake and experience).
6. Replace the seals and worn pairs.
7. Collect it in reverse order.
8. Make a fall-up.
The quality of the assembly directly depends on the cleanliness in the working area and the correctness of the seal installation. The use of sealants instead of original rings is unacceptable in high pressure nodes.
Selection of spare parts and compatibility
When selecting parts according to the scheme, it is important to pay attention not only to the model of the car, but also to the model of the car. node-maker. The same machine could be fitted with ZF, TRW or Koyo rails, and their internal design would be different. The number of the part on the body is your main reference point.
Remakes are complete and partial. The full includes all rings, cuffs and bushings, which is ideal for major repairs. Partial can contain only the oil shaft, which is suitable for eliminating light leakage. The plan will help you understand what you are changing.
When buying a used node, compare its appearance with the reference scheme. The absence of fastening elements, traces of rough intervention, slimmed slits on the shaft - all this is visible on a close inspection. Restored reiki is often better than new Chinese reiki, but only if restored professionally.
- ✅ Original: Perfect match, high price, quality guarantee.
- ✅ Analogue (Lemforder, Sasic): Good quality, comparable to the original, the price is lower.
- ✅ Restored: Cheaper new, but requires a master check, the resource depends on the quality of repair.
- ✅ China (noname): Lottery, often soft metal, low resource, risk of re-breaking.
⚠️ Attention: Never use sealants to fix threaded joints inside a hydraulic circuit. Sealant particles can clog the distributor channels, which will cause the system to fail. Use only mechanical fixation or threaded fixtures if specified by the manufacturer.
Frequently Asked Questions (FAQ)
Can I drive if the steering rack is knocking?
You can drive, but not for long and extremely carefully. Knocking means there is a backlash that will progress. At any moment, the reiki may jam or thrust may snatch, resulting in loss of control. In addition, the knock is often accompanied by vibration, destroying adjacent suspension nodes.
How often should I change the fluid in the GUR?
Manufacturers often say that the liquid is poured for the entire life, but practice shows that it is better to change every 60-80 thousand kilometers. Old liquid loses its properties, is saturated with metal shavings and water, which kills the glands and pump.
Why does the steering error burn after replacing the rails?
In modern cars with EUR or adaptive GUR, software adaptation (steering sensor calibration) is often required after replacing the unit or removing the battery. Without a special scanner or performing a certain taxiing procedure, the error will not disappear.
Which is better: restore the old rake or buy a new one?
If the shafts are intact, the shafts do not have deep production, and the problem is only in the wear of the rubber bands - restoration makes sense and saves up to 50% of funds. If there is corrosion on the shaft (mirror) or the production of a pair of gear-rail - only a replacement, since it is impossible to restore the geometry of the metal.