Any owner Skoda Octavia A7 sooner or later he encounters the problem of knocking in the steering rack. This is a characteristic feature of the MQB platform, which, with a mileage of over 80β100 thousand kilometers, begins to manifest itself as a characteristic rattling sound when driving over uneven surfaces. Many car owners immediately run to a service center to replace the unit, but often the problem is solved simply steering rack adjustment, which restores clarity of control and eliminates extraneous sounds.
Ignoring the symptoms can lead to accelerated gear wear and costly repairs. In this article we will look in detail at how to do it yourself diagnostics, understand the cause of the knocking and perform the tightening procedure without resorting to the services of specialized service stations. It is important to understand that Skoda Octavia A7 is equipped with an electromechanical rack, and the approach to it differs from its hydraulic counterparts.
Diagnosing knocking and determining the cause of the problem
Before you crawl under the car, you need to accurately determine the source of the sound. Owners often confuse rack knocking with steering shaft beating or play in the silent blocks of levers. For an accurate diagnosis, you will need an assistant and an inspection hole or overpass. Sit behind the wheel and ask your partner to move the steering wheel left and right with a small amplitude while you listen to the sounds below.
If a knock is clearly heard in the area of the steering rack and is accompanied by a delay in the reaction of the wheel to turning the steering wheel, this is a sure sign of wear on the support sleeve or a gap in the gearing. Steering rack on Octavia A7 has a plastic bushing that wears out over time, creating free movement. In some cases, the problem lies not in the rack itself, but in the universal joint of the steering shaft.
Pay attention to the nature of the knock. If the sound occurs only when driving over small bumps and disappears on a flat road, this is a classic symptom of a broken support bushing. If the teeth are heavily worn, the knocking will be constant and accompanied by vibration on the steering wheel. Electromechanical amplifier may make extraneous sounds if the torque sensor is faulty, but this can only be diagnosed by a scanner.
β οΈ Attention: If during diagnostics you notice leakage of grease from under the boots or play in the shaft itself, simple adjustment may not help. In such cases, a complete replacement of the unit or a major overhaul with replacement of bushings is required.
Preparing tools and necessary materials
To complete the work, you will need a standard mechanic's kit and several specific keys. The main requirement is to have a high-quality torque wrench, since overtightening can lead to the steering wheel jamming. You don't need to buy expensive equipment, but having the right tools is critical to safety.
The list of necessities includes: a set of sockets (including 10, 13, 16 mm), a 4 mm hexagon for the adjusting bolt, grease for the rack (special lithium or graphite), rags and penetrating lubricant (such as WD-40) for unscrewing the fastening bolts. A circlip puller will also come in handy if you need to replace the bushings.
- π§ Torque wrench with range up to 100 Nm
- π§ Adjustment wrench (hexagon) or special socket for 12
- π§ Steering rack lubricant (Liqui Moly or VAG original is recommended)
- π§ Penetrating fluid for processing threaded joints
Don't forget to have a jack and safety stands ready. Working under the machine using only a jack is strictly prohibited. Remove the front wheels to gain full access to the tie rods and crankcase guard.
Step-by-step instructions for adjusting the steering rack
The process begins with lifting the car and removing the engine protection. Locate the adjustment bolt on the rack body. On Skoda Octavia A7 it is often closed with a plastic plug that needs to be carefully pryed off. Clean the area around the bolt from dirt to prevent debris from getting inside the mechanism when rotating.
Before tightening, you must loosen the locknut on the adjusting bolt. Use two wrenches: one holds the bolt itself, the second unscrews the nut. Do not use excessive force as the thread may become soured. After loosening the nut, you can begin the main procedure.
βοΈ Preparing for adjustment
Rotate the adjusting bolt clockwise to tighten the rack. Do this gradually, half a turn at a time, and check the play each time. Gap in engagement should be minimal, but without noticeable resistance when turning the steering wheel. Tightening is dangerous because it can lead to the steering wheel jamming while driving, which can lead to an accident.
Once the optimum result is achieved, tighten the locknut while holding the bolt from turning. Check the steering wheel again for free play and play. Reinstall the protective plug. Tightening torque lock nuts are usually around 20-25 Nm, but it's best to check the specifications for your specific modification.
β οΈ Attention: Do not use an impact tool to tighten the adjusting bolt! This may deform the rack housing or damage the gear train, rendering the assembly unsuitable for further use.
The main purpose of the adjustment is to eliminate play without creating excess friction, which could lead to the steering wheel jamming or overheating of the power amplifier motor.
Typical errors and operating nuances
Many owners make the mistake of trying to tighten the rack without first diagnosing it. If the knocking noise is caused by wear on the driveshaft, adjustment will have no effect and you will only waste time. Always check all steering components before starting work.
Another common mistake is using the wrong lubricant. Conventional oil or lithol may not provide the required properties at low temperatures, which will lead to jamming of the mechanism in winter. Use only specialized formulations recommended by the manufacturer VAG.
What happens if you over tighten the rail?
Over-tightening increases friction in the engagement. This leads to rapid wear of the teeth, overheating of the electric motor of the amplifier and, in the worst case, to the steering wheel jamming at high speed, which is extremely dangerous.
It is also worth considering that on some versions Octavia A7 with electronic control there is steering adaptation. After adjustment, it may be necessary to reset errors or calibrate the steering angle sensor through a diagnostic scanner.
- β Using lubricants with aggressive additives
- β Adjustment on a cold engine without preheating (for hydraulics, but also important for checking rigidity)
- β Ignoring the condition of anthers and seals
Table of tightening torques and tolerances
For correct assembly and safe operation, it is necessary to strictly observe the tightening torques of fasteners. Below is the current data for most modifications Skoda Octavia A7 with electromechanical rail.
| element | Tightening torque (Nm) | Tolerance (+/-) | Note |
|---|---|---|---|
| Attaching the rack to the body | 50 | 10 | Use new fasteners |
| Tie rod mount | 35 | 5 | Check the condition of the stopper |
| Adjustment bolt | 10 | 2 | Pre-lift |
| Bolt lock nut | 25 | 5 | Commit after setup |
| Steering wheel rod | 40 | 5 | Attaching to the rack shaft |
Compliance with these values ensures that the unit will operate stably and will not create unexpected loads on the suspension. If you are not confident in your abilities, it is better to entrust this work to professionals, as mistakes here can cost your life.
- Once a year
- Only when there is a knock
- Once every 5 years
- Never checked
When adjustment does not help and repair is needed
In some cases, a simple lift does not work. This occurs when the wear of mechanical parts has reached a critical stage. If you feel βdead spotsβ or jamming when turning the steering wheel, most likely the rack itself or the worm pair inside the electric motor is worn out.
Also, adjustment is pointless if the seals or anthers are damaged. Water and dirt trapped inside can cause corrosion of the teeth, which cannot be corrected by tightening. In such cases it is required major renovation or complete replacement of the unit with a new one or a contract one.
Pay attention to the cost of repairs. Sometimes replacing the entire rack assembly is cheaper than a complex repair involving the replacement of many small parts and subsequent adaptation. Electronic control unit may block the operation of the amplifier if critical errors are detected, which will require flashing.
If after adjustment the knocking noise disappears, but a hum appears when the steering wheel is rotated in place, this is a sign of overtightening. Immediately loosen the bolt a quarter turn.
FAQ: Frequently asked questions
How long does it take to adjust the rack on an Octavia A7?
On average, the process takes from 40 minutes to 1.5 hours, depending on the experience of the technician and the condition of the fasteners. If guards and wheels need to be removed, the time may increase.
Is it possible to adjust the rack without removing the wheel?
Theoretically, it is possible if you have access to the bolt, but this is extremely inconvenient and dangerous. It is recommended to remove the wheels and protection for a full inspection and convenient operation of the tool.
Is it necessary to do a wheel alignment after adjustment?
If you have not unscrewed the tie rods from the levers, the wheel alignment will not be affected. However, after any work on the steering, it is recommended to check the wheel alignment for safety.
Why does the knocking come back after a short time?
This may mean that the bushings are worn critically and they do not hold tension, or the adjustment was performed incorrectly. In this case, replacement of bushings or repair of the unit will be required.
Do I need a scanner to adjust the rack?
A scanner is not needed for mechanical tightening. However, it may be required to reset errors after work or calibrate the steering angle sensor (if it has worked).
β οΈ Attention: Adjusting the steering rack on the Skoda Octavia A7 is a responsible procedure that requires precision. An error may lead to loss of control of the vehicle!