Analysis of the Reasons for the Bulldozer's deviation

The oil intake in the steering clutch chamber causes the friction plates to slip

The torque from the rear axle is transmitted to the drive wheels through the steering clutch and the final transmission mechanism, pushing the bulldozer forward or backward. The left and right sets of steering clutches are respectively installed in two clearance chambers of the rear axle housing, and skeleton-type self-tightening oil seals are used to prevent the gear oil in the central transmission chamber and the final transmission chamber from flowing into the clearance chambers. If the oil seal on one side ages and fails, the gear oil will continuously seep into the spacer chamber, causing the friction plates of this clutch group to slip. When the bulldozer is running empty, due to the small load, the slippage is not obvious, and thus it can maintain a straight line of travel. When the bulldozer shovel was lowered to start pushing, the load suddenly increased, and the friction plates in this group immediately slipped, causing the bulldozer to deviate. In order to make the bulldozer move in a straight line, the driver has to frequently pull the steering lever of the other side to keep it in a semi-engaged state, so as to achieve synchronous rotation of the left and right steering clutches. This not only makes driving very strenuous, but also reduces work efficiency and accelerates the wear of the friction plates. For this purpose, you can first unscrew the oil drain plug under the rear axle compartment. If there is accumulated oil flowing out, it indicates that the compartment has leaked oil and should be cleaned immediately. The specific method is as follows:

Drain the accumulated oil in the compartment while it is still hot.

(2) At the same time, drain the gear oil from the central transmission chamber and the final transmission chambers on both sides to prevent cleaning kerosene from entering and diluting and deteriorating the gear oil.

(3) Inject 3 liters of cleaning kerosene into the partition room.

(4) Let the bulldozer travel forward and backward for 5 to 8 minutes. During the travel, do not pull the steering control lever to prevent oil stains from adhering to the friction plates.

(5) Drain the cleaning oil and add an additional 3 liters of clean kerosene.

(6) Pull the left and right steering control levers all the way to the bottom, allowing the pusher to idle in place in second gear for 5 to 8 minutes, so that the driving and driven plates of the steering clutch can be thoroughly cleaned.

(7) After the bulldozer is turned off, unscrew the oil drain plug in the spacer and let it stand for 4 to 5 hours to ensure that the cleaning oil is completely drained.

(8) After all the kerosene that has entered the central transmission chamber and the final transmission chamber has been drained, add the specified amount of gear oil.

(9) Grease the release bearings of the left and right steering clutches.

After the above cleaning, the bulldozer can generally eliminate the phenomenon of deviation. However, if after working for a period of time, when the oil drain plug of the interval chamber is unscrewed, a large amount of accumulated oil flows out again, it indicates that the oil leakage in this chamber is severe. The self-tightening oil seal of the frame should be inspected or replaced to completely eliminate the oil leakage fault, so that the bulldozer can return to normal.

2. Wear or erosion failure of the steering clutch components

If there is very little oil accumulation in the spacer chamber, the left and right steering clutches should be removed respectively for disassembly and inspection.

Due to the quality of the driver's operation skills and the differences in the working environment, after long-term use, the two sets of steering clutch friction plates of the bulldozer may experience uneven wear, erosion, warping or insufficient elasticity of the large and small springs, resulting in inconsistent output torque. When a bulldozer is running empty, it can still go straight because the required torque is not large. However, when it is loaded, the steering clutch cannot rotate synchronously, and thus the bulldozer veers off course. Friction plates that have been eroded, deformed or worn beyond the limit should be replaced. The elastic force of the large and small compression springs should be checked. If necessary, they should be replaced to restore the same working performance of the left and right steering clutches.

To ensure that the steering clutch can be completely disengaged and brake in time, the free travel between the steering control lever and the brake pedal should also be correctly adjusted.

(1) Adjustment of the free travel of the steering lever

Loosen the clamping screw on the push rod adjustment sleeve, and turn the adjustment sleeve to change the length of the steering clutch push rod until the free travel of the steering control lever is within the range of 60-80mm. After adjustment, tighten the clamping screw and adjust the other steering control lever in the same way.

(2) Adjustment of the free travel of the brake pedal

Release the brake pedal to the stop bar close to the floor of the driver's cabin. Turn the adjustment fork of the brake lever to change the length of the lever, tilt the brake lever backward by 15°, screw the brake band tension nut all the way down and then return it 6-7 turns, so that the free travel of the brake pedal is controlled between 65-85mm. Finally, press the brake pedal all the way down and lock it. Then, loosen the lock nut on the adjustment screw at the bottom of the housing. After screwing the screw all the way down, return it by 1 to 1.5 turns. You will then get the appropriate brake band clearance.