Owners Skoda Octavia Tour Often faced with a characteristic hum, which is enhanced when gaining speed and changes the tone in corners. This sound almost always indicates wear and tear. front wheel bearing. Given the age of many cars in this lineup, the life of parts often comes to an end, requiring immediate intervention to keep the road safe.
Ignoring the problem can lead to a jamming of the wheel or destruction of the hub, which is fraught with serious consequences. In this article, we will discuss in detail how to independently determine the fault, choose a quality one. wheel bearing and correctly perform its replacement without contacting the car service.
How to recognize a bearing failure
The first and most obvious sign is the sound. A hum resembling the work of a cargo wheel appears when moving and does not disappear after the engine stops. It is important to distinguish this fault from tire noise or brake system problems. If the sound changes when you turn the steering wheel, this is a reliable indicator of breakdown.
When turning left, the load is shifted to the right wheel. If the hum is amplified at this moment, then it is defective. right bearing. Conversely, if the sound disappears when you turn to the left, then the problem is in the right element, since it is unloaded. This is the basic method of rapid diagnostics.
- ๐ Constant hum or howl, depending on the speed of movement.
- ๐ The wheels are swayed by his hands over the top and bottom.
- ๐ Friction or grinding when the wheel is rotated in place.
- ๐ Vibration transmitted to the steering wheel or floor of the car.
Sometimes the problem is accompanied by vibration, which is transmitted through the body. If you feel that the steering wheel is shaking at certain speeds, and when braking the effect is enhanced, it is worth checking not only the bearings, but also the condition. brake discs. However, in most cases, it is the wear and tear hubs It's the root cause.
โ ๏ธ Warning: If you find a strong backlash during the diagnosis or hear metal grinding, operation of the car is prohibited until the fault is corrected.
Design features on Octavia Tour
By car Skoda Octavia Tour (A4) a non-shallable hub structure with a double-row roller bearing is used. This means that the repair of the bearing itself is impossible - it requires replacing the entire unit. The design is integrated into the wheel hub, making it easier to replace, but requires certain tools to dismantle.
An important feature is the presence of a sensor. ABS (anti-lock system) which is built into the bearing assembly. When buying a spare part, be sure to check for a magnetic ring and a sensor connector. On some versions, the sensor can be removable, but most often it is assembled with a bearing.
The choice of manufacturer plays a key role. Cheap analogues often have short-lived separators and poor-quality lubrication. It is recommended to give preference to original parts or proven brands, such as: SKF, SNR or FAG. Saving on this part can lead to re-repair after a couple of thousand kilometers.
- Original Skoda
- SKF
- FAG
- SNR
- Other
Selection of quality spare parts
The spare parts market is saturated with fakes, so the choice should be approached cautiously. The original detail from Skoda Often comes in boxes with the logo of the VW Group, but inside may lie a product from the same concern. SKF or Luk. It is normal, the main thing is to check the holograms and the quality of the packaging.
When ordering by VIN-code you are guaranteed to receive a part that is suitable for your configuration. Make sure the specification is correct. hub-size And there's an ABS sensor. Sometimes on the front axle are installed different nodes for front-wheel drive and all-wheel drive versions (4x4).
- โ Original Part Number (check by catalogue).
- โ The presence of a magnetic ring of a speed sensor.
- โ Packaging with protective elements against counterfeiting.
- โ Set of fasteners (bolts of the hub, nut of the bearing).
If you are buying an analogue, carefully study the reviews about the manufacturer. Some brands offer good value for money, but their resource may be lower than the original. You should not be looking for the lowest price, because wheel bearing It's working under a tremendous load.
Before buying, be sure to remove the wheel and measure the diameter of the hub with a rod to make sure that the selected spare part is compatible with your car.
Necessary tools and preparation
To replace the front bearing, you will need a set of specialized tools. Without it, the process can drag on or damage parts. A standard set of keys will not be enough, since the nut of the hub has a large tightening moment and often clings.
You will need a jack and reliable stands ("goats"), as you will have to work under the car. Be sure to prepare. puller for pressing an old bearing or a large hydraulic press. If there is no press, you can use mandrels and a hammer, but it requires skill.
โ๏ธ Preparing for replacement
Also, do not forget about penetrating lubricant (WD-40 or analog) for processing the caliper and hub mount bolts. If the bolts are very rusty, it is better to treat them in advance so as not to break the thread when unscrewing. The presence of a dynamometer key is necessary for the correct tightening of all connections.
โ ๏ธ Attention: The nut of the hub has a very high puffing moment. Use an extension cord for the collar and apply a considerable force to loosen it.
Step-by-step replacement instructions
The first step is to dismantle the wheel and disconnect the brake system. Remove the cap of the hub nut, unscrew the caliper and hang it on the wire so as not to damage the brake hose. Then remove the brake disc.
Next, you need to disconnect the ABS sensor and unscrew the bolts of the rotary fist attachment to the shock absorber rack and lever. This is the most time-consuming part of the job that requires patience. Often the bolts are boiling, and they have to be warmed up or used by a percussion tool.
When the swivel fist is free, you can remove the old hub and press the bearing. New bearing pressed into the rotary fist with a mandrel resting on the outer ring. Do not press on the inner ring or separator.
Common mistakes when pressing
If you press on the inner ring of the bearing, you will damage the separator and rollers. This will lead to a quick failure of the node even with proper installation. Always press the ring that will contact the body (usually the outer one).
After installing the new bearing and hub, assemble the node in reverse order. Tighten the hub nut at the recommended moment, and then install a new splint or pin the nut if the design provides for it. Donโt forget to connect the ABS sensor.
Correct tightening of the hub nut is critical: overtightening will lead to overheating of the bearing, and undertightening will lead to rapid destruction of the unit due to play.
Specifications and tightening torques
For successful repairs, the manufacturer's specifications must be strictly followed. Tightening torques for various suspension elements on Octavia Tour may vary depending on the year of manufacture, but there are general standards.
| Fastening element | Tightening torque (Nm) | Note |
|---|---|---|
| Hub nut | 250-300 | Use a torque wrench |
| Wheel bolts | 120 | Tighten crosswise |
| Caliper bolts | 30 | Check the condition of the guides |
| Bolts of the strut to the knuckle | 50 + additional turn | Often a 90 degree rotation is required |
Remember that the hub nut is often a one-time design. After unscrewing it, it is better to replace it with a new one. Also carefully inspect the threads on the axle shaft - if it is damaged, the nut will not create the required clamping force.
After assembly, be sure to check the operation of the ABS system. There should be no warning light on the dashboard. If the lamp lights up, the sensor may not be connected or the wire may be damaged. In some cases, errors need to be reset by the scanner.
Frequently asked questions and answers (FAQ)
Is it possible to replace only the bearing and not the entire assembly?
In most cases on Skoda Octavia Tour the bearing is part of a non-separable assembly. Replacing only the internal element requires special equipment and skill, but is often impractical due to the risk of damage to the housing. It is better to replace the entire assembly.
Is it necessary to do a wheel alignment after replacing a bearing?
If you did not remove the levers and did not change the suspension settings, the wheel alignment should not be changed. However, if you have unscrewed the bolts securing the strut to the knuckle, it is recommended to check the wheel alignment angles to avoid uneven tire wear.
Why does the new bearing hum immediately after replacement?
This may be due to incorrect installation (misalignment during pressing), damage to the separator, or a defective part. It is also possible that you damaged the ABS sensor or did not fully insert it into the seat. Check all connections.
How often should front bearings be replaced?
The service life of a high-quality bearing ranges from 80 to 150 thousand kilometers. However, the condition is affected by the quality of the roads, driving style and the presence of protective covers. Regularly checking the condition of the suspension will help avoid sudden breakdowns.
Replacement front wheel bearing - the task can be done on your own if you have the tools and accuracy. The main thing is to take your time, observe the tightening torques and use high-quality spare parts. This will ensure the safety of your ride and the durability of the suspension.
โ ๏ธ Attention: Never use an impact tool to tighten the hub nut - this will disrupt the geometry of the bearing and cause instantaneous failure.