Forklift torque converter is one of the indispensable and important parts of automatic transmission. It is installed on the flywheel of the engine. Its function is to transfer the power of the engine to the gear transmission mechanism of the automatic transmission, and has a certain function of stepless transmission. The torque converter consists of a pump wheel, a turbine and a guide wheel. The hydraulic fluid is installed between the engine and the transmission, and uses the hydraulic fluid as the working medium to transmit torque, variable torque, variable speed and clutch.

Forklift truck torque converter failure mainly shows that the engine throttle is fully open and the forklift truck inlet oil pressure of the forklift torque converter is less than the standard value under the condition of zero speed working condition.

Diagnostic steps: First pull out the dipstick and see if the torque converter oil level is between the two lines. If the oil level is normal, check for leaks inside and outside the pipe, and if there are leaks, they should be eliminated on a case-by-case basis.

If the inlet and outlet oil pipes are well sealed, the torque converter inlet and outlet pressure valves should be checked. If the pressure valve cannot be closed, remove the pressure valve and check whether the components are worn, the oil circuit and holes are smooth, and the spring is permanently deformed. If the component wear exceeds the limit, it should be replaced or repaired.

If the pressure valve is working properly, remove the oil line and filter and inspect. If there is a blockage, the sediment should be cleared. If the oil line is clear, the hydraulic pump needs to be serviced and replaced if necessary.

The forklift torque converter leaks oil, mainly showing obvious traces of oil leakage at the joint surface of forklift torque converter rear cover and pump wheel and the connection between pump wheel and wheel hub.

If there is an oil leak at the connection between the torque converter and the engine, put a blank piece of paper on the window of the machining hole. If the engine drops oil from the connection after the engine starts, it may be that the bolt (or connection rivet) on the pump wheel and the pump hub are loose, the seal is aging, and the oil plug is loose or the gasket is damaged. At this time, the bolts (or rivets) should be tightened and rechecked to see if there is still oil leakage, and if there is still oil leakage, the seal should be replaced.

If there is a large oil leak at the connection between the torque converter and the engine, the pump wheel cover should be disassembled and replaced.

If the oil leakage site is located at the filling port or discharge port plug, the sealing of the screw plug should be checked first. If the screw plug is too loose, it should be retightened; if the thread plug is not loose, the thread hole should be checked for cracks.

Forklift torque converter noise, mainly manifested as forklift torque converter work, it has metal friction sound and impact sound inside.

First check whether the torque converter and engine connecting bolts are reliable, if the fixed bolts are loose, they should be tightened and reach the specified torque; if the fixed bolts are tightened normally, some hydraulic oil should be released from the torque converter to check whether there are impurities in the oil. If the oil is clean and metal-free, the bearing should be loose or worn; if the released oil contains fine powdered aluminum powder, the internal parts should be abnormally worn.

Forklift driving powerless: After starting in gear and increasing engine speed, forklift driving powerless and slow.

First, check if the pressure gauge indicates that the pressure is within the normal range. If the pressure is too low, the influencing factors should be identified according to the second type of failure. If the pressure is normal and weak, damage to the seal ring inside the torque converter, wear and tear of the pump wheel or damage to the turbine blades may be the cause.

Failure of the transmission friction clutch can also result in a weak transmission. At this time, the end cover of the friction clutch can be disassembled to check if the seal ring is worn or aged, and if the end cover is grooved, which can be replaced or repaired as appropriate. If the friction clutch is working properly, the torque converter should be disassembled to view the wear of the seal ring, turbine and pump wheel.

If you can’t start the engine, the spool of the torque converter aircraft inlet and outlet oil pressure valve may be stuck or the clutch can’t be put into gear. You can disassemble the inlet and outlet valves to see if the spool is stuck. If there is a stuck phenomenon, should be cleaned, so that the free movement, if the spool is good, you should replace the hydraulic fluid. If the spool is good, the clutch may be “stuck”, can not hang up the gear, the clutch should be disassembled to eliminate the fault.