As the power transmission mechanism of automobiles, the gearbox is also one of the three major parts of the car. Therefore, it is very important to maintain and keep the gearbox in good working order.
The types of gearboxes are manual transmissions, automatic transmissions, etc., and different types of transmissions have different structures and working principles. Below we will introduce some methods, precautions and tips for daily maintenance of gearbox.
First, the use of gearbox common sense
1. Common sense in the use of manual transmission
1) When the reverse gear is engaged, the vehicle must be stopped.
The clutch pedal is pressed all the way down and then engaged in reverse gear, which makes it easier to achieve gear mesh. When the reverse gear is engaged, the sound of "bell" is the normal sound of the meshing of the reverse gear set and the action of the shift mechanism inside the transmission, indicating that the gear shift is in place.
2) When engaging the forward gear, make sure the clutch pedal is pressed all the way down and the gear lever is pushed into place.
3) pay attention to control the engine speed when upshifting, the cold car state is recommended to shift gears at the engine speed of 2000 rpm, and the hot car state is recommended to shift gears at the engine speed of 2500-2800 rpm, so that the frequency of shift difficulties can be effectively reduced.
For manual transmissions, the recommended shift speed can be referred to the vehicle instruction manual.
4) pay attention to the control of vehicle speed during downshift operation: it is recommended that the 3rd gear should not be higher than 35 km h for 2nd gear, and the 2nd gear should not be higher than 18 km h for 1st gear, at this time the synchronizer is easy to achieve synchronous downshift.
2. Common sense in the use of automatic transmission
The engine can only be started when the gear lever is in P or N gear.
1) Key points for the use of R gear and P gear
The vehicle must come to a stop before being in R or P gear, even if it is a very slow slide.
In any case, you should confirm that the gear lever is hanging on the P gear before leaving the vehicle. When the vehicle is stopped, if the transmission lever is not in P gear, the gear lever should be re-attached to P gear before starting the vehicle again.
2) Move out of the point of the P gear
The gear lever can only be removed after the brake pedal is pressed, otherwise the transmission will be damaged.
If you temporarily stop in P gear and press the brake pedal for more than 1 minute, you need to release the brake pedal first and then press the brake pedal again to remove the gear lever from P gear.
3) Key points of use of N gear
This gear can be used when the driver does not leave the vehicle for a short stop. It is strictly forbidden to coast in N gear (neutral) when the vehicle is moving forward.
If, while driving, you accidentally engage neutral, you should leave the engine idle before shifting to D or M gear.
When waiting for a red light for a long time, shift the gear to nth gear, press the brake pedal or activate the parking brake to save fuel and protect the transmission.
4) The main point of using the D gear
In this gear, the automatic transmission automatically selects the right time to shift gears according to the vehicle's driving conditions to ensure fuel economy and smooth shifting. In automatic transmission mode, the accelerator pedal can be pressed or released slowly and smoothly for better smoother shifting.
When the gear lever is in D or R gear, do not turn off the engine.
In the event of a running abnormality, the transmission locks into one gear and does not exceed 100 km/h.
Do not press the brake pedal and the accelerator pedal at the same time. Both braking and acceleration must be operated by the right foot only. Pressing both pedals at the same time may damage the transmission.
In the event of a vehicle breakdown or other accident, when towing or towing services are required, be sure to contact a professional for vehicle towing or towing operations.
Second, the gearbox use skills
1. Precautions for manual transmission shifting
The manual transmission is mechanically controlled, so it can be slightly different from the hydraulically and electronically controlled automatic transmission during gear shifting. In order to protect the transmission and clutch and maximize its value and longevity, the driver needs to pay attention to the following when operating:
1) When the car is driving, the gearbox is running at high speed. In non-emergency situations, when the driver is shifting gears, the clutch pedal should be pressed to the bottom before shifting gears to avoid damage to the inside of the gearbox caused by incomplete clutch disengagement.
2) When the speed is higher than 24kmh, it is strictly forbidden to lower the gear to 1st gear, at this time, there will be a large shift force when changing 1st gear, otherwise the clutch will be damaged or cause serious wear of the synchronizer ring.
3) Shift gears during the acceleration process, when the engine speed reaches about 2000 rpm, first put the gear position in neutral and then hang in, and the gear shift will be smoother.
2. Precautions when using automatic transmission
1) Don't switch gears too often. Frequent gear shifts will cause the electronic control system to repeatedly adjust the degree of engagement of the clutch, increasing its wear and failure rate, and also affecting the vehicle's smoothness and fuel consumption. During normal driving, D gear should be kept unchanged; When you need to slow down or stop, you should brake early and switch to N or P gear.
2) Don't apply the brakes for a long time in D gear. Applying the brakes for a long time in D gear will cause the torque converter to be unable to transmit power to the gearbox, which will increase the temperature of the transmission oil and accelerate the aging of the transmission oil. When waiting for a red light or stopping, you should switch to N or P gear.
3) Don't drag with reverse gear。Dragging with reverse gear will exceed the bearing capacity of the reverse clutch, and it is easy to damage the reverse clutch. If the vehicle is stuck in mud or snow, you should try to get out of the situation with forward gear first, and if you still can't move, you can slightly shake the vehicle back and forth with reverse gear, but not too hard or for too long to avoid causing more damage.
3. How to park the automatic transmission model correctly?
Step 1: Hit the brakes, slow down to stop, and continue to press the brake pedal after stopping;
Step 2: After stopping, hang into the n gear, pull up the handbrake, and release the footbrake;
Step 3: Press the foot brake again, hang the gear to "P" position, then release the brake pedal and turn off the ignition.
3. Daily maintenance of gearbox
For the maintenance of the gearbox, the most important thing is the transmission oil. Transmission oil not only provides lubrication for the gearbox, but also provides heat dissipation for the gears of the transmission, and more importantly, in the AT transmission and some more advanced dual-clutch transmissions, the transmission oil also plays a role in transmitting power through the torque converter. Therefore, it is necessary to regularly check whether the transmission oil level is normal, and after a certain mileage, the transmission oil also needs to be replaced in time.
For each different model and transmission, the interval for changing the transmission oil is also different. If the car maintenance manual gives a recommended oil change interval, then you can replace it according to the actual mileage used.
Under normal circumstances, the manual transmission of the car can be checked about every 40,000 kilometers and replaced every 100,000 kilometers.
For CVT transmissions, AT transmissions, and wet dual-clutch transmissions, the responsibility of the transmission fluid inside the transmission is heavier, and the oil change interval is relatively shorter. It is possible to follow a check every 2 years or every 30,000 km driven, and a complete change of automatic transmission oil every 6 80,000 km. However, you can also fluctuate the oil change interval to a certain extent according to the smoothness of the gearbox shift or the daily use conditions.
Speaking of which, I believe that everyone has a certain understanding of the use of the gearbox and daily maintenance, and will be more handy in the future car maintenance process.
For friends who are ready to buy a car, there are many types of car gearboxes now, if you don't know which kind of gearbox to buy? You can refer to the following article:
There are so many types of gearboxes, how to choose? An article tells you.