How to tell if the gearbox is good or bad

Nowadays, the mainstream models on the market are automatic transmission, manual transmission, and automatic manual transmission. How to judge the quality of the gearbox? Here we analyze it as automatic and manual. Please consider the last one!

Manual gearbox

Some people choose manual gearboxes because of their budget, others choose manual gearboxes for driving pleasure. Some people choose manual gearboxes because of years of habit. Regardless of the reason, manual gearboxes are still the current consumer. Compared with the automatic gearbox with novel technology, manual gearbox has received less attention than before. As a result, some car owners have insufficient experience, resulting in complaints about the poor use of the gearbox after buying the car. Here are 4 ways to distinguish.

1. Transmission supplier

The so-called famous teachers make good students, and a good gearbox supplier often determines the quality of the gearbox. Relatively speaking, joint venture brands generally choose three major gearbox manufacturers, such as Aisin, ZF, and JATCO, to ensure quality and reliability; independent brands often choose local suppliers , Such as Chongqing Qijiang, Chongqing Qingshan, Zhejiang Zhongma, etc., are indeed inferior to the three major suppliers in the design of gearboxes. Of course, there are also self-sufficient companies, such as Volkswagen, whose level is also higher than that of local brands. In a word: foreign gearbox suppliers are better than local gearbox suppliers.

2. Gear ratio arrangement

We can understand the gear ratio of the gearbox as "clearance". The "clearance" of each gear should be reasonably distributed. If it is too large, it will easily affect the smoothness of power connection, and it is easy to downshift. For example, during a test drive, we will find that some cars have a large change from first gear to second gear. It seems that the power is suddenly in the mid-range and requires big feet to fill up the oil. And some cars have a step-by-step change in the first and second gears. go. Therefore, gearboxes with poor gear ratios often require you to deliberately perform cumbersome operations such as refilling oil and controlling brakes.

3. Clear gears

The clear gear position affects the success of the gear shifting and setting. Presumably everyone will encounter the embarrassment of not being able to enter the gear when learning to drive? And this is the problem of gear clarity. This is mainly the several machinery inside the gearbox. For the coordination of components, we only need to know that a gearbox with clear gears is basically in place in one step, without deliberately pushing in, while a good gearbox will automatically operate as long as the gear lever is pushed to a certain critical point. In position, this is the so-called "inhalation feeling". Of course, a poor gearbox will have a "jerky feeling", which can clearly detect the frictional blocking feeling when entering the gear.

4. Shifting stroke

The shift stroke is divided into horizontal and longitudinal strokes, which affect the sensory speed of the driver when shifting gears, and to a certain extent affect the driving pleasure. Generally speaking, the shorter the stroke, the feeling is that the vehicle shifts faster, and there is no need to stretch the arms, and the body feels relatively comfortable, but the resistance when shifting is slightly larger. At present, most sports cars will use short-stroke manual gearboxes, while domestic models use moderate shifting strokes, while MPVs and vans use long-strokes to reduce shift resistance.

Basically, as long as the supplier of the gearbox can determine the quality of this gearbox, in the actual experience, we can also judge the smoothness of the power connection, the clearness of the gears, the sense of inhalation and the sense of blocking, And the length of the shift stroke to determine the quality of the gearbox.

automatic transmission

The automatic transmission is different from the manual transmission of the general gear set mechanism. Its structure contains multiple sets of friction plates and brake pads, and uses a special hydraulic shaft at the same time. Therefore, for ordinary car owners, the disassembly and maintenance of the automatic transmission Both require professional knowledge and technology, but through simple methods, you can get a glimpse of the pros and cons of their working conditions.

1. The automatic shifting time is too long or too short.

Generally, automatic transmissions have specific shifting speed and vehicle speed. If you find that the shifting time is suddenly too long or too short, it means that the transmission ratio of the gearbox is disproportionate. At the same time, you will feel that the engine speed is too high. What's more, the gearbox does not change gears, which indicates that there is a problem with the gearbox.

2. The car slipped or impacted.

If the car does not go when the D or R gear is engaged, or the car reacts slowly and then impacts, or the engine speed is high but the vehicle speed is very slow, it means that there is a problem with the mechanical transmission part of the gearbox.

3. Peculiar smell is generated in the cabinet.

The gearbox body relies on hydraulic oil to work. When the oil temperature is too high, some combustion will occur, and these peculiar smells will be transmitted, which means that some executive parts in the gearbox body are not working properly.

Beware of traps in the automatic transmission repair market. When the automatic transmission of a car fails, most car owners will drive the car to a car 4S shop for inspection and repair. Some 4S shops generally make a pre-quotation before disassembly and inspection, and the price is 10,000 to 20,000 yuan (mid-class sedans and high-end sedans) ) Or 30,000-40,000 (premium cars), and after the actual disassembly and inspection, the actual quotation will have more than doubled. Because of the lack of professional maintenance and testing equipment and technical capabilities for automatic transmissions, 4S shops have to replace the internal gearboxes. Highly priced components, such as valve bodies, torque converters, etc., are close to the price of a new gearbox assembly, which often makes car owners miserable. It is recommended that you go to a professional repair point instead of blindly choosing a 4S shop. Of course, if you are a trench, please ignore!