What are the common faults of dual-clutch transmissions?

Under congested urban traffic conditions, vehicles frequently start and stop, and the clutch of the dual-clutch transmission needs to be constantly engaged and disengaged, which will cause a large amount of friction heat between the clutch plates. If the heat dissipation system cannot dissipate the heat in time, the clutch will overheat.

 

Clutch overheating:

Under congested urban traffic conditions, vehicles frequently start and stop, and the clutch of the dual-clutch transmission needs to be constantly engaged and disengaged, which will cause a large amount of friction heat between the clutch plates. If the heat dissipation system cannot dissipate the heat in time, the clutch will overheat. Overheating will cause the clutch plate to wear more, deform, or even burn, resulting in a decrease in vehicle power and gear shifting frustration. In severe cases, the vehicle will be unable to drive.

Clutch wear: After long-term use, the clutch plate will gradually wear out. When worn to a certain extent, it will affect the normal operation of the clutch. For example, the clutch is not tightly engaged, resulting in poor power transmission and vehicle acceleration; or when shifting, the clutch plate wears unevenly, causing the gear shift frustration to increase significantly.

 

Clutch jitter:

The clutch's pressure plate, friction plate and other components are not installed with enough precision, or deformed or loosened during use, which will cause the clutch to jitter during operation. This jitter will be transmitted to the vehicle body through the transmission system, so that the driver can clearly feel the vibration of the vehicle in the car, affecting driving comfort.

 

Electromechanical unit failure:

Sensor failure: Various sensors in the electromechanical unit are responsible for monitoring the working status of the gearbox, such as speed sensors, temperature sensors, etc. If the sensor fails, the signal transmitted to the control unit will be inaccurate, and the control unit will not be able to correctly control the gearshift operation of the gearbox, resulting in abnormal gearshifting, such as gearshift delay, unsmooth gearshifting, sudden gear jump, etc.

 

Solenoid valve failure:

The solenoid valve is a key component in the electromechanical unit that controls the flow of hydraulic oil. Its working state directly affects the engagement and separation of the clutch and the action of the shifting mechanism. The solenoid valve may fail due to problems such as valve core jamming, coil disconnection or short circuit, resulting in the hydraulic system not being able to work properly, causing gearshift failure, which may cause the vehicle to be unable to shift or lose power in severe cases

Oil leakage failure: Aging of seals: There are many seals inside the dual-clutch gearbox, such as oil seals, sealing rings, etc., which are used to prevent gearbox oil leakage. With the increase of use time, these seals will gradually age, harden, and lose elasticity, resulting in a decrease in sealing effect and oil leakage. Gearbox oil leakage will not only cause the gearbox oil level to drop, affecting the normal lubrication and heat dissipation of the gearbox, but also pollute the chassis and environment of the vehicle

Shell damage: When the vehicle is involved in collisions, scratches, or is impacted by external forces, the housing of the dual-clutch gearbox may be damaged. Shell damage will cause the oil inside the gearbox to leak, and in severe cases, impurities may enter the gearbox and damage the gearbox parts.

Abnormal noise failure: Gear abnormal noise: During long-term use, the gears inside the gearbox may become larger or uneven due to wear, tooth surface peeling, gear shaft bending, etc. When the gears rotate, abnormal noise will be generated. This abnormal noise is usually more obvious during vehicle driving, especially when shifting or accelerating or decelerating.

Bearing abnormal noise: The bearings in the gearbox are responsible for supporting rotating parts such as gear shafts. If the bearings are worn, damaged, or poorly lubricated, abnormal noise will be generated. The sound of abnormal bearing noise is usually a continuous buzzing or rattling sound, and the frequency and volume of the abnormal noise will change with the change of vehicle speed.

 

Electronic control system failure:

The electronic control module of the dual-clutch transmission is the "brain" of the entire transmission, responsible for receiving signals from various sensors and controlling the gearshift operation of the transmission based on these signals. If the control module fails, the transmission will not work properly, and there may be shift confusion, fault lights on, etc.

 

Line failure:

The lines connecting the various components of the transmission may fail due to wear, aging, short circuit, etc., resulting in interruption or abnormal signal transmission. For example, a short circuit may cause the sensor signal to fail to be correctly transmitted to the control module, or the command issued by the control module cannot be transmitted to the execution component, thereby causing a transmission failure.