Gearbox parts TRANSMISSION Assembly 272200753 / 2BS315A for XCMG parts

The automatic transmission of the loader is composed of a hydraulic Torque Converter, a planetary gear mechanism and a control system. The hydraulic torque converter and the control valve body are the two most expensive assemblies in the automatic transmission.
Diagnosis ideas and maintenance methods for common faults of hydraulic torque converter:
1. The one-way clutch supporting the guide wheel in the torque converter slips.
(1) Failure phenomenon When the vehicle has poor acceleration below 30~50km/h, the vehicle speed rises slowly, and the acceleration is good after passing the low speed zone, it is likely that the one-way clutch supporting the guide wheel in the torque converter is slipping .
(2) Fault diagnosis method After the Engine has warmed up, plug the 4 wheels with triangle wood or bricks, tighten the parking brake, step on the foot brake pedal, stare at the engine tachometer, and fully depress the accelerator, such as The stall speed of the engine was significantly lower than the specified value, indicating that the one-way clutch supporting the guide wheel in the torque converter was slipping.
(3) Fault analysis The torque converter increases torque at low speed. The guide wheel changes the direction of fluid flow. After the one-way clutch supporting the guide wheel in the torque converter slips, the guide wheel does not have the support of the one-way clutch. It is impossible to change the direction of the liquid flow under the circumstances. In this way, the flow direction of the liquid flow returning through the guide wheel is opposite to the rotation direction of the pump wheel, and the engine needs to overcome the additional load caused by the reverse liquid flow, so the hydraulic torque converter becomes a hydraulic coupling, and the low-speed torque increase becomes low-speed The torque is reduced, so the car accelerates poorly in the low-speed zone (the torque converter increases the torque working condition).
(4) Maintenance method Replace the torque converter assembly or use a lathe to open the torque converter, and then replace the guide wheel and one-way clutch to eliminate the fault.
2. The one-way clutch supporting the guide wheel in the torque converter is stuck
(1) Trouble phenomenon The car starts and runs normally at medium and low speeds, but there is no high speed. The maximum speed is only about 80~90km/h when the throttle is gently stepped on; the maximum speed is only about 110~120km/h when the throttle opening is increased.
(2) Fault diagnosis method When the one-way clutch supporting the guide wheel is stuck, it feels a bit like engine exhaust is not smooth, but it is difficult to start a cold car when the engine exhaust is not smooth. Open the upper cover of the air filter and remove the filter element. When the engine accelerates rapidly, the exhaust gas recirculation can be seen here, and the one-way clutch supporting the guide wheel is stuck, which will not cause the exhaust gas recirculation. From the color of the oil, everything is normal, and the fault can not be found with the fault diagnosis instrument. The engine stalls and rotates normally.
(3) Maintenance method Replace the hydraulic torque converter assembly or use a lathe to open the hydraulic torque converter, and then replace the guide wheel and one-way clutch to eliminate the fault.