Find loader appear sometimes steering without representation, trouble began factors: loader of the primary system pressure is too low, includes the loading machine oil quantity deficiency, steering pump serious wear and safety relief valve dysfunction; valve function of poor form low pilot pressure system; device to install the wrong or damaged; flow enlarge valve leaks or spool clamping stagnation; steering cylinder leak serious; system tubing save or blocked. Example: find the loader appear sometimes to no representation problems found hanging block jogging or walking can be left and right steering, but not in gear for in-situ operation turn the steering wheel, two steering wheel only left and right roller 15 degrees or so. Find loader sometimes appear to have no representation problems of the machine selection flow to expand the hydraulic system, and operating equipment hydraulic system is independent of each other. Steering hydraulic system mainly by the steering pump, steering gear, pressure reducing valve, flow expansion valve, steering cylinder, oil filter and radiator, etc., in which the pressure reducing valve and the steering device attributed to the pilot system, the other is attributed to the main circuit. Finds the loader appear sometimes to no representation problems factors: main system pressure is too low, contains oil tank volume deficiency, steering pump serious wear and safety relief valve dysfunction; valve function of poor form low pilot pressure system; steering device install the wrong or damaged; flow expansion valve leakage or valve clamping stagnation; steering cylinder leak serious; system tubing save or blocking. Find fault points in accordance with the order of "from Jane to fan". First and foremost, you can remove the steering gear installed wrong perhaps. Secondly, the pressure gauge is used to measure the main pressure and the pilot pressure, the pressure value is 12MPa and 2.5MPa, both in the normal range. In order to very good inspection results, and automatically adjust the pressure of high 2MPa, the test machine when the trouble as usual, this shows that the amount of fuel tank is sufficient, relief valve, pressure relief valve and steering pump are no abnormal. Again, with the swap approach to install a reliable flow of the valve and the flow of the steering device, the test machine found that problems still exist, so the flow to remove the expansion valve and the steering gear is faulty. Finally, the steering cylinder and the system of oil pipe collapse, view the piston oil seal outstanding, cylinder wall without wear and tear, pull marks, no internal savings and obstruction. After the above view, it can be concluded that the steering hydraulic system is normal. Find loader appear sometimes steering without representation, faults and cleaning again and try out the machine shoveling material, feel loading machine operation and powerful, survey hinge point not found card lag phenomenon, thus infer that faults in the front drive axle. In order to verify the discriminant is not accurate, first remove both sides of the wheel side cover and pull out the half shaft, and then operate the steering wheel turning, at the moment can be smooth rolling steering wheel, which can determine the fault point is the front drive bridge. From the front drive axle gear oil, found a small number of iron. Remove the drive shaft, and remove the front drive axle main drive assembly, differentiation of the differential gear part of the planetary gear cracking, cross shaft minor deformation. Replacement of the new differential assembly, according to the technical standards for the replacement of the test machine, the machine turned to normal. Analysis of the wheel loader sometimes rendered to the normal operation of the differential fault factors of representation, the dynamic self deceleration follower gear sequentially the differential case, cross shaft, planetary gear, axle shaft gear, a half axle, passed to the left and right driving wheel. The planetary gear can revolve along half axis, and can rotate around the axis of itself (i.e., cross axis of rotation). When loading the turning machine, planetary gear of revolution and rotation combination formed complex movement, the left and right half shaft gear with different angular velocity of rotation, and on the left and right wheel tangent direction added one direction instead of reaction force. The additional reaction force is formed on both sides of the planet gear to make the rotation of the planet gear. Differential in the operation if the larger impact load, the planetary gear fatigue cracking occurs, the cross shaft deformation. When the loader gear micro or traveling, because of left and right half shaft speed range (i.e., angular velocity is unequal), differential gears, rub each other less resistance, the planetary gear can be of both the revolution and rotation of the motor complex, complete differential speed effect and smooth finish turning. Pivot steering angular velocity is zero, and because in the planetary gear cracking, a cross shaft deformation, friction resistance increases, the planetary gear differential, half shaft gear rolling is blocked differential would lose poor speed effect, eventually resulting in loading machine can not be turning in place. The above is sometimes presented no problem to image factors and solutions to find loaders, friends remember