Etc.).
Moreover, gearbox repair is also a complex and expensive procedure. This is especially true when it comes to automatic transmissions, high-quality bulkheads or overhauls of automatic transmissions. For this reason, it is important not only, but also to fix any signs that indicate possible problems with the transmission and gearbox.
Next, we will talk about why extraneous sounds arise and what they indicate during the operation of the gearbox, for what reasons the gearbox is buzzing, what to do if the gearbox of a mechanic or automatic howls, etc.
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The box buzzed: the main reasons
During operation, one of the most common signs of a malfunction or breakdown is a rumble in the gearbox. At the same time, the gearbox noise or hum may differ in tone and strength, occur only in some or all gears, etc.
- So, let's start with the automatic transmission. In this case, it is important to understand that the automatic transmission (variator, robotic mechanics, hydromechanical machine) is somewhat quieter than the manual transmission, and should not make obvious extraneous sounds.
If the automatic transmission is buzzing or making noise, first of all, you need to check, as well as its condition and quality. The box itself should also be inspected for possible transmission fluid leaks.
In a situation where the unit itself is dry, everything is also in order with the oil, or it was replaced with a separately recommended ATF, in parallel, but the hum in the box does not go away, then diagnostics are required without fail.
As a rule, this means that the box will need to be removed and disassembled for troubleshooting, and such work is expensive if it is not done on its own, that is, at a specialized car service.
As for the common causes of the hum of automatic transmissions, experts identify:
- A manual transmission or automatic transmission with mileage is characterized by abrasion / damage or wear of the parts of the main pair. As a result, backlashes appear, which become a source of noise;
- Gear wear means that there is strong friction in the interface area, loads increase, noise increases, the box buzzes;
- If the CVT variator is buzzing, in some cases this is a sure sign of serious wear or malfunctions, indicating that the box will soon completely fail.
- In some situations, it may not be the box itself that may buzz, but. In other words, there is play in the places where the axle shafts are attached, resulting in a strong gearbox hum.
- We also add that in automatic transmissions bearings often hum and make noise, abrasion and damage to the teeth on the drive gear or on the shaft lead to backlash and hum (both in one gear and in several).
In other words, in most cases it is not possible to normally operate a car with a buzzing automatic transmission. Moreover, depending on the type of gearbox, such operation may even be unsafe, since it is possible to open the clutch of the box - a robot, problems with acceleration during overtaking, lane changes and other maneuvers.
- Now let's move on to the manual transmission. As in the case of an automatic transmission, the rumble of a manual transmission and various noises in the mechanic's box arise for various reasons. At the same time, there can be quite a lot of such reasons, starting with a lack of gear oil and ending with defects and damage to individual parts.
At the same time, it is a mistake to believe that a manual transmission is much more reliable than an automatic transmission, that is, such a transmission can be constantly subjected to loads, aggressively operate the car, etc. In fact, this unit may well buzz or fail already by 100-150 thousand km.
If we talk about repairing a manual transmission, it is much cheaper to repair a manual transmission than an automatic one. At the same time, high-quality repairs still involve the replacement of a number of elements. Also, the performance will directly depend on the qualifications of the specialists who perform the overhaul of the gearbox.
So, in the list of causes of hum in a manual transmission, we can distinguish:
- Insufficient amount of lubricant. If there is little oil in the gearbox, the symptoms often manifest as the box howling and buzzing in higher gears (for example, gearbox hum in 5th, 6th gear).
There may be no extraneous noise in lower gears. As a rule, in this case, we can say that there is oil, but it is not enough. At the same time, gears and other parts of the manual transmission are subject to increased wear.
- Another cause of noise is wear or defective replacement of parts of the main pair. At the same time, the box can buzz for a long time, but then the unit will finally break down.
Also, worn drive bearings lead to noise in the gearbox, which first emit a hum, after which they simply collapse after a short time. As a result, serious consequences and a significant increase in the cost of repairs can be expected.
- Often the gears of the gears become the cause of the hum, and only one gearbox gear can buzz. This indicates that problems arise only with individual gears of the gear that began to buzz;
- It is also possible that noise will appear after repairing the box, which is due to assembly errors (inaccurate fitting of the shaft and gears, etc.);
- Also, which indicates malfunctions in the gear shift mechanism (speeds are difficult to turn on, there are problems with gear selection, gearboxes are worn out, malfunctions, etc.);
A rumble appeared in the gearbox: what should the driver do
As you can see, extraneous sounds in the form of noise, gearbox hum or crunch can appear in both automatic and manual transmissions. Moreover, the gearbox can suddenly hum if there is an emergency transmission oil leak.
This means that you need to inspect the unit for smudges. If leaks are visible, then leaks will need to be repaired. It is also optimal to stop further operation of the vehicle, that is (especially in the case of an automatic gearbox).
If this is not possible, then after topping up the oil, you should immediately go by car to the service, avoiding loads on the gearbox. It is not recommended to use the "stop-leak" type without urgent need.
In cases where the box is dry, but there is a hum, such a malfunction tends to progress. In other words, with mileage, the noise will only increase. In the case of automatic transmission, it is better not to delay and immediately go for diagnostics.
As for the mechanics, a box with a hum in many cases is operated further, avoiding high loads. At the same time, it is important to understand that such operation in the future can lead to more serious consequences and an increase in repair costs. For example, if the main pair, gears, synchronizers, etc. are worn out, you can ride, but in this case, the loads on other parts of the box are also increased.
It turns out that the best solution is to conduct timely diagnostics in a specialized gearbox repair service when any extraneous sounds appear (hum, noise, howl or crunch of the gearbox). If necessary, experienced specialists will disassemble the box, determine the cause of the malfunction, perform troubleshooting and preliminarily draw up an estimate, which will indicate the amount of repair.
We also add that when selecting spare parts, it is better to refuse cheap taxes, that is, use only original spare parts or high-quality substitutes from third-party manufacturers. Only in this case, you can count on high-quality work and an acceptable gearbox resource after repair.
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Gears turn on tight or do not turn on speeds on a manual gearbox: the main causes of malfunction and possible malfunctions.
