Lock-up clutch failures on vehicles equipped with automatic transmission will have a huge impact

Common faults of lock up clutch: lock up clutch engagement, not separation, not poor bonding and slipping. Multiple fault phenomenon is diverse, so to grasp its working principle, characteristics and the method of fault analysis is very important.
First, the road test, the vehicle without the law appear jitter between 40 – 80km / h. The first detection of the engine, but found no fault. This may be caused by other factors. So the computer detecting instrument reads the data flow, found that when the locking clutch (TCC) joint, especially the ground station to the 40% – 60%, the vehicle will appear jitter phenomenon. The fault is composed of TCC binding caused by bad. But the results are caused by bad and which part?Fault may lie electronically controlled, hydraulic and mechanical systems which part. Of course, there are some special circumstances, such as when the throttle is closed, apply the brakes, acceleration or deceleration, shift, oil temperature below 60 ℃ Rotary temperature is too high and gear in the following block 3, etc., because these time lock the clutch is engaged.

The locking clutch engagement and separation by computer (PCM) through the lock up clutch (TCC) to control electromagnetic. Computer analyzed according to the solar term door position sensor, speed sensor, a turbine shaft, gear shift moment sensor, and brake switch signal, to the TCC electromagnetic valve provides a duty cycle signal, changed the TCC electromagnetic valve opening, thereby controlling the action of clutch. For the TCC work, computer is through the rotational speed of the engine and the turbine shaft (input shaft) of the speed difference to monitor.When the locking clutch does not work, the engine speed should be greater than the turbine shaft speed is 200 300r / min; in the lock up clutch engagement process, both the differential speed should be reduced gradually; when the locking clutch is completely engaged, the rotational speed difference should be zero. Therefore, can be observed through the engine speed and the rotational speed of the turbine (input shaft speed difference between the clutch) to determine the working state and extent.

On the hydraulic part of the fault can be determined by measuring the hydraulic pressure. So this car gearbox oil pressure test carried out. Road test, jitter occurs when the TCC engagement and found no oil pressure fluctuations and anomalies. To further determine if this part is faulty hydraulic transmission, fold down the valve and install test template, using compressed air to be tested. The results showed that the TCC various hydraulic valves and valve oil works well, the hydraulic part of the fault can be basically ruled out the possibility.

As for the mechanical part, due to the inability of dismantling, so only through the exclusion of other aspects of the failure to determine. The detection and analysis of the above several aspects, determine the fault is likely only in mechanical parts, namely the torque converter lockup clutch.

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Engine water pump failure or damage, repairs only need six steps

The pump is one of the important parts of the automobile engine cooling system, the water pump is the role of the cooling liquid pressure, ensure the circulation flow in the cooling system, accelerate the heat emission. As a long-term operation of the device, the use of the process, the water pump will be a failure, how to examine and repair the fault, a lot of people will feel that the examination is very complex, fault repair directly,in fact, there are some minor glitches owners completely can be solved, do not spend “money wasted.”The car in use, if the pump is faulty or damaged, do the following inspection and repair.
1.Check the pump body and the belt pulley has no wear and damage, should be replaced when necessary. Check the water pump shaft bending, there is no shaft neck wear, the shaft end thread is not damaged. Check the impeller blade has no broken, the shaft hole wear is serious. Check the seal wear degree and bakelite washer, if more than the limit of use should be replaced with new parts. Check the bearing wear, gap available surface measurement of bearing, such as more than 0.10mm, should be the replacement of the new bearings.

2.After removing the pump, according to the order of decomposition. After the decomposition should be part cleaning, and then check them one by one, to see if there is crack, damage and wear, such as serious defects should be replaced.

3.Seal and seat repair: seal, such as wear and tear from the slots that can be polished emery cloth, such as excessive wear should be replaced even; seal seat if rough scratches, available flat reamer or a lathe repair. During the overhaul should be replaced with a new seal components.

4.On the pump body with the following injury allows welding repair: Length 3Omm less, does not extend to the bearing hole cracks; engagement with the cylinder head flange with breaking parts; seal bore for damage. Water pump shaft bending shall not exceed 0.05mm, or should be replaced. Impeller blades damaged should be replaced. Pump Shaft badly worn should be replaced or repaired casement.

5.Check the water pump bearing rotating flexible or abnormal noise, such as that the bearing has a problem, should be replaced.

6.The pump is assembled, hand rotation, the pump shaft and no blocking, impeller and pump shell without rubbing. Then check the pump discharge, if any problem, should check and eliminate the cause. If the pump fails, the coolant will arrive at the corresponding place cannot, its performance will not be effective, thus affecting the working condition of the engine. Therefore, we must strengthen the pump check.

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