5 maintenance methods for bulldozers

1. Correct bulldozer track tension

To ensure the longevity of bulldozer tracks, it is essential to maintain the correct tension. Over-tightening can cause excessive stress on the track pins and bushes, leading to premature wear. In addition, the tension of the idler spring can wear out the shaft and bushes, often resulting in a semi-circular wear pattern on the idler bushing. This not only stretches the track shoes' pitches but also diminishes the efficiency of mechanical transmission, leading to a loss of power from the engine to the sprocket and tracks.

Low track tension can lead to detachment from the idler and track rollers, resulting in misalignment. This causes the track to fluctuate and impact irregularly, leading to abnormal wear on both the idler and carrier rollers.

Add grease to the oil injection nozzle to tighten the track, or release grease form the oil release nozzle to loosen it. When the track shoe pitch is stretched to a certain extent, indicating that a set of track shoes needs to be removed, it's time for maintenance. Check for abnormal wear on the mating surfaces, segment tooth surface, and bushing. Maintenance methods may include turning the pin and bushing over, replacing excessively worn pins and bushings, or replacing the entire track shoe assembly.

2. Idler correct position

Proper idler's alignment is crucial for the longevity of the undercarriage. The clearance between the idler roller guide plate and the track frame should be adjusted to the standard clearance of 0.5 - 1.0mm, to ensure optimal performance and extend the life of the travel mechanism. Shims are used to adjust the gap between the guide plate and bearing. If the gap is too large, the shims are removed, on the contrary, shims are added. The maximum permissible clearance is 3.00mm.

The track links, or track chain, and the bushings are crucial parts of a bulldozer’s undercarriage system. Over time, these components can wear down, causing the pitch (the distance between the links) to stretch. This can lead to poor meshing between the driving wheel and the bushing, resulting in damage and abnormal wear.

This wear and tear can cause issues like snaking, flapping, and impact, which can significantly reduce the lifespan of the travel mechanism. If the pitch cannot be restored by adjusting the tension, flipping the track pin and bushing is necessary to achieve the correct track pitch.

There are two methods for deciding when to flip the track pin and bushing. One method involves checking for a track pitch elongation of 3mm, and the other involves checking for wear of the bushing’s outer diameter of 3mm.

However, it’s important to note that the exact procedures and measurements can vary depending on the specific model of the bulldozer and the manufacturer’s guidelines. Always refer to the operation and maintenance manual of the specific equipment for the most accurate information.

3. Timely Tighten Bolts and Nuts

When the bolts of the travel mechanism become loose, they are prone to breakage or loss, leading to a series of malfunctions. Daily maintenance should include checking the following bolts: the mounting bolts of the track roller and carrier roller, the mounting bolts of the segments (sprockets), the mounting bolts of the track shoes, and the mounting bolts of the track roller guard plate.

4. Regular Lubrication

Proper lubrication of the travel mechanism is crucial. Many track roller bearings are ‘burned out’ and become scrap due to oil leakage that is not detected in time. It is generally believed that oil may leak from the following five places: from the block ring and shaft due to a damaged or poor O-ring; from the outside of the block ring and the track roller due to poor contact with the floating seal ring or O-ring defects; from the liner and the roller due to a bad O-ring between the track roller and the liner; from the oil filling plug due to loosening of the oil filling port screw plug or damage to the conical screw plug sealing the seat hole; and from the cover and the roller due to a bad O-ring. Therefore, regular checks of these parts should be conducted, and oil should be added or replaced according to the lubrication cycle of each part.

5. Crack Inspection

Maintenance of bulldozers should include timely inspections for cracks in the travel mechanism, with prompt welding repairs and reinforcement as needed.