Diagnostics and replacement front wheel bearing on cars Skoda Octavia A5 is one of the most common operations during suspension maintenance. Structurally, this part is a complex unit integrated into the wheel hub, which experiences enormous loads when driving on Russian roads. Failure of this element can lead not only to increased noise, but also to a critical loss of controllability at high speed.
Many owners Octavia A5 They mistakenly believe that knocking in the front suspension is a problem with shock absorbers or levers, but it is hub often becomes a source of extraneous sounds. Timely detection of malfunctions allows you to avoid costly repairs to the brake system and discs, which can be damaged if the unit jams.
Design features of the unit on the Skoda Octavia A5
On the platform PQ35, which underlies Octavia A5, the front suspension is made according to the MacPherson design using double row ball bearings closed type. These elements do not require lubrication during operation and are designed for the entire service life of the vehicle, however, the reality of operation makes its own adjustments. Wheel bearing is pressed into the steering knuckle and has an inner ring that fits tightly onto the wheel hub.
The design feature is that on cars with anti-lock braking system (ABS) In one of the bearing rings is built a magnetic inductor. This sensor transmits a signal about the speed of rotation of the wheel to the electronic control unit. If the inductor is damaged or contaminated, the ABS system can produce an error even with a proper sensor.
When replacing the unit, it is necessary to take into account that on front-wheel drive versions Octavia A5 The load is distributed unevenly, which often leads to rapid wear of the inner row of balls. Steering knuckle It is made of iron or steel, and if it is not dismantled properly, it can crack, which will require replacing the entire part in the assembly.
It is important to understand that wheel hub And the bearings are indissoluble elements in the factory version. An attempt to disassemble the knot, knock out old balls and press new ones, as a rule, ends in a repeated breakage after several thousand kilometers of run.
- ๐ ๏ธ The unit is designed for high radial and axial loads when driving on irregularities.
- ๐ The integrated ABS sensor requires careful handling when installing a new bearing.
- โ๏ธ The design provides for the use of a special tool for pressing without damaging the rings.
Symptoms of malfunction and diagnostic methods
The first and most obvious sign of wear and tear is the characteristic hum or howl, which intensifies with increasing speed. This sound is often confused with the noise of tires, but when diagnosing it is important to note that the hum front wheel bearing It changes its tone when turning the steering wheel. If the sound is amplified when you turn to the left, then the right side is under load, and vice versa.
The second symptom may be vibration transmitted to the steering wheel or the body of the car. Such vibration usually does not depend on the operation of the engine, but manifests itself precisely when moving, which indicates the beating of the rotating assembly. In advanced cases, when wedging the bearing, the smell of burning from overheated brake discs occurs.
For accurate diagnosis, you need to hang the wheel and turn it manually. If there is a backlash or crunch inside the hub, wheel hub It should be replaced immediately. It is also possible to sway the wheel at the top and bottom for backlash, but this method is less informative compared to checking the rotation.
โ ๏ธ Warning: If you hear a sharp metal grinding or feel a strong vibration on the steering wheel when braking, stop driving immediately. Jammed front wheel bearing It can cause the wheel to be completely blocked on the go, which can lead to an accident.
- ๐ A hum that changes tone when turning the steering wheel in different directions.
- ๐ Vibration, which is enhanced during acceleration and does not depend on engine speed.
- ๐ฅ The smell of burning oil or brake dust due to overheating of the friction node.
- Less than 50,000 km
- 50,000 - 100,000 km
- 100,000 - 150,000 km
- More than 150,000 km
Selection of spare parts: original or high-quality analogue
The spare parts market offers a huge selection of solutions for Skoda Octavia A5But the quality of bearings varies from elite to downright low-quality. Original article hubs ล koda is usually duplicated by the brands of the VAG Group. However, overpaying for a box with an automakerโs logo is not always advisable if there are proven component manufacturers.
The most reliable suppliers are considered to be companies. SKF, SNR, FAG and Timken. These brands produce bearings using the same technologies as the original, but often have better packaging and warranty. Avoid buying cheap analogues of nameless brands, as they often do not withstand 10 thousand kilometers of mileage.
When choosing, pay attention to the presence of new wheel mounting bolts and lock nuts in the set. Hub nut It is a disposable item and its reuse is not allowed. Also check if the ABS sensor comes with it if it is integrated into the node.
| Brand | Bearing type | Indicative resource | Features |
|---|---|---|---|
| SKF | Double row ball | 120,000+ km | High accuracy, reliable ABS sensor |
| FAG | Double row ball | 100,000+ km | Excellent protection from moisture, rigid construction |
| SNR | Double row ball | 90,000+ km | Wide availability, good price/quality ratio |
| Chinese analogues | Various types | 10,000 - 30,000 km | Low reliability, risk of rapid destruction |
- ๐ฆ Check the packaging for holograms and brand serial numbers.
- ๐ง Make sure that the kit has new bolts and lock nuts.
- ๐ฐ Avoid โnounaimeโ manufacturers, even if the price seems attractive.
Preparing tools and work area
For high-quality replacement work front wheel bearing You will need a professional set of tools. A conventional jack and a set of keys will not be enough, since the node is pressed with great effort. Make sure to prepare a hydraulic press or special detachers for hubs and bearings.
You will also need a dynamometer key to tighten critical connections. Hub nut It is delayed with a moment of about 200-250 Nm depending on the modification of the engine, so the use of a conventional key is unacceptable. Do not forget about the means of protection: glasses, gloves and stops for the car.
Work is better carried out on a hole or lift to ensure free access to the bottom of the suspension. If you are working on the ground, make sure the car is securely fixed on the stands after lifting the jack.
โ๏ธ Preparing for replacement
Step-by-step instructions for replacing a bearing
We start the process with the dismantling of the wheel and unscrewing the caliper. Brake caliper You need to hang on the wire so as not to damage the brake hose. Next, unscrew the guide calipers and carefully remove it along with the brake pads. Then we unscrew the nut of the hub attachment, which may be boiling, so use penetrating lubricant and extension cord.
Next, we'll disassemble the brake disc. If it is boiled, you can gently knock it with a hammer through a wooden spacer. Then disconnect the ABS sensor connector if it is connected separately and unscrew the mount bolts. steering knuckle To the lever and the shock rack.
The most important step is to remove the old bearing. To do this, you need to use a press or a removable, relying on the inner ring. Never press the outer ring when knocking out the inner ring, as this will destroy the bearing separator.. After removing the old knot, carefully clean the seat in the swivel fist of rust and dirt.
The new bearing is pressed into the rotary fist to the point. The force should be applied only to the outer ring so as not to damage the inner paths. After installing the fist with a new bearing, collect the suspension in reverse order, not forgetting to replace the hub lock nut and tighten it with the right moment.
โ ๏ธ Warning: When pressing a new bearing into a swivel fist, make sure it sits to the point. The slightest distortion will lead to rapid destruction of the knot and possible jamming of the wheel on the move.
- ๐ง Use the press for removal and installation, do not apply shock force directly.
- ๐งน Clean the seat of rust to ensure a tight fit.
- โ๏ธ Replace the locking nut of the hub with a new one, as it is disposable.
Common mistakes when replacing
1. Using an old hub bolt, which leads to its stretching and unscrewing. 2. Pressing the bearing through the inner ring, which damages the rolling tracks. 3. Ignoring the cleaning of the landing place, leading to backlash.
Technical nuances and post-installation checks
After the suspension assembly, it is necessary to check the operation of the ABS system. Connect the diagnostic scanner and make sure there are no errors on the sensors of the speed of rotation of the wheels. If the error is not reset, it is possible that the sensor was damaged during dismantling or incorrectly installed. front wheel bearing. Also check the absence of backlash in the hub by shaking the wheel with your hands.
The first 50-100 kilometers after replacement should operate the car in a gentle mode. Avoid sharp accelerations and braking, as well as driving through deep pits. After 1000 km, it is recommended to re-check the tightening of the bolts and the nuts of the hub, as they may sit down a little.
It is also important to check the descent-fall, as the dismantling of the suspension elements could change the angles of the wheels. This is particularly relevant for Octavia A5where the geometry of the suspension is sensitive to changes. Wheel alignment It should be done only after the complete assembly and inspection of all the connections.
Before starting work, be sure to take a picture of the circuitry of connecting the wires of the ABS sensor to avoid confusion during assembly. This will save time and eliminate errors when connecting.
Qualitative replacement of the hub bearing requires the use of special tools and new consumables. Savings on the press or nut can result in re-repairs on the road.
Cost of work and savings
Replacement cost front wheel bearing The service varies depending on the region and level of the car service. On average, the work on replacing one node costs from 2000 to 4000 rubles. If you decide to do the work yourself, you will save that amount, but take the time to prepare and find the tool.
The cost of the bearing itself is from 3000 to 8000 rubles for a quality original or brand. In this price is also worth laying the cost of new bolts, nuts and possibly an ABS sensor. The final estimate for self-replacement will be 2-3 times lower than in the service.
However, remember that if you donโt have experience with press, the risk of damaging the swivel fist or installing the knot incorrectly is high. In this case, the cost of correcting the error may exceed the cost of the professional wizard. Wheel bearing This is a security detail, the selection and installation of which must be approached responsibly.
- ๐ธ Savings on self-replacement are 50-70% of the cost of the service.
- ๐ ๏ธ The cost of a quality bearing exceeds 3000 rubles per unit.
- โฑ๏ธ The time of work with the tool takes 2-3 hours per wheel.
FAQ: Frequently asked questions
Can I drive with a faulty bearing?
It's not recommended. Wear of the bearing can cause it to jam, which will cause the wheel to lock and loss of handling. In addition, the destruction of the knot can damage the brake disc and the swivel fist.
Do you change bearings in pairs?
Preferably. If one bearing has worn, the second one is likely in a similar condition. Replacing both will save time and money in the future, and will ensure that the car behaves evenly on the road.
Is it necessary to do a wheel alignment after replacement?
Yes, I will. Dismantling and installing suspension elements, especially levers and racks, inevitably change the angles of installation of the wheels. Without adjustment, the tyres will wear unevenly.
What tool is needed for replacement?
The main tool is a hydraulic press or a removable for hub bearings. You will also need a dynamometer key, a set of heads, a jack and stands. Without a press, replacing the bearing correctly is almost impossible.
How long does a new bearing last?
High-quality bearing with proper installation and operation will serve from 80 to 150 thousand kilometers of mileage. The service life depends on the quality of roads, driving style and operating conditions of the car.