1. Torque converter failure
(1) The torque converter control pressure and outlet pressure are too low. The reason is that the oil level is too low, the control pressure valve or outlet pressure valve is stuck in the open position, and the hydraulic pump is damaged. Oil should be added, stuck dirt should be removed, and the hydraulic pump should be repaired or replaced.
(2) The torque converter oil temperature is too high. The reason is that the main components in the torque converter do not meet the requirements. First check the torque converter oil. If there is a lot of aluminum powder in the oil, the oil temperature rises sharply, the drive does not move, and the speed drops, it is caused by damage to individual parts of the torque converter. At this time, the high-speed rotating pump in the torque converter Under the action of eccentric force or centrifugal force, the center bearing of the wheel, turbine and other components is poorly lubricated, resulting in bearing damage, friction and heating of the turbine and pump wheel. At this time, the torque converter should be inspected and damaged parts should be replaced. If there is less aluminum dust during the inspection, it means that the machining size error of the main components in the torque converter is too large, and motion interference occurs between the pump wheel, turbine and guide wheel, resulting in excessive temperature. The torque converter should be disassembled and inspected, and faulty parts should be repaired or replaced.
2. Main clutch failure
When the gearbox has difficulty in shifting, unclear separation of the main clutch, gear shifting or slipping, it is mainly due to improper clearance between the main clutch release plate and the release bearing. At this time, adjustments should be made to maintain a distance of 2.5 mm between the one-way thrust bearing and the separation plate. In addition, you should also pay attention to the following points when making adjustments:
(1) When measuring the distance between the outer end surface of the main clutch separation disc and the outer end surface of the friction disc hub, the end face swing of the separation disc should be measured at the same time, and the swing should be controlled within 0.15-0.20 mm.
(2) The main clutch has four separation claws supporting the separation disk. During adjustment, there may be a gap between one or two separation claws and the separation disk. Therefore, when adjusting, press the separation disk with your hands in all directions. If any “missing legs” are found, adjust and eliminate them in time. Even if there is no “missing leg” when pressed by hand, tap the separation plate with a wooden stick or hammer, and then press and check with your hands until there is no “missing leg” and the end face swing meets the requirements to avoid uneven stress on the separation rod. , The friction disc is warped and deformed, causing early wear.
(3) When the friction disc needs to be replaced due to burnout, the copper-based powder metallurgy material adhered to the friction surface of the driving disc and pressure plate must be polished clean to avoid adhesion with the friction material of the new disc and accelerate the wear of the new disc.
3. Failure of shovel rotation mechanism
The meshing clearance between the drive gear and the rotating large ring gear is too large. This will destroy the matching relationship between the rotary follower valve and the two rotary joint arms, and the movements between the hydraulic cylinders will interfere with each other, especially at the dead center position. One cylinder will make the rotary joint arm rotate forward, while the other cylinder will make the rotary joint arm rotate forward. The reverse rotation of the joint arm can easily cause the weak parts of the mechanism, especially the welding joint between the rotary joint arm and the drive shaft, to be damaged or even broken.During maintenance, first check and adjust the meshing gap between the gears. If the gap is too large, adjust the position of the rotating large ring gear by adjusting the bolts or replace the gears to make the meshing gap
gap meets the requirements. The slewing arm broke at the weld. The gear meshing clearance should be adjusted first and then repaired.When repairing, first find out the relative position of the two slewing joint arms. If you use the original parts to repair
If the original welding position can be found correctly, just weld it according to the original welding position; if the slewing joint arm and drive shaft are updated, or it is difficult to find the original welding position, the two slewing joints must be re-positioned. The relative position of the arm before welding. Finally, adjust the relative position of the rotary follower valve and the two rotary joint arms.
If you are interested in other maintenance methods for graders, you can continue to follow us. CCMIE—Professional second-hand car merchant
Post time: Jan-25-2024