The undercarriage of a bulldozer typically represents an average of 50% of the machine's parts and service costs. Therefore, it is crucial to select the appropriate undercarriage from the outset and to maintain it properly.
To choose the correct undercarriage, several key questions must be considered:
How long will I own this machine?
How many hours per week will I operate this machine?
What are the typical ground and soil conditions in my work area?
What impact conditions will I face?
What attachments will be used on the machine?
What are the typical grades and slopes at my job sites?
Maintenance is the best method to reduce ownership and operating costs, extend the lifespan of the undercarriage, and prevent failures. One of the primary actions to undertake is a daily inspection, checking the majority of components to ensure everything is functioning properly and exhibiting no abnormal wear.
The first items to check are the outer edges of the tracks to ensure that no bolts are missing or loose. Next, inspect the track link assembly and bushings to ensure there are no abnormal scalloping or pits on the bushings, as these may indicate wear from forward or reverse movement, or stepping.
Following this, examine the sprocket segment. Within the sprocket pocket, check for any mushrooming of the iron, which could indicate high-speed forward or reverse movement. Then, inspect the idlers for any ridging or abnormal adjustments, ensuring that everything appears to be in good condition. Afterward, verify that all track rollers are secure and that there are no obstructions preventing their operation.
Lastly, assess the carrier rollers to ensure that debris does not accumulate on top of the undercarriage, which may impede their rotation. If the carrier rollers cannot rotate, the tracks will roll over them, wearing down flat spots on the tops of the rollers, which accelerates wear and reduces the undercarriage's lifespan.
Another critical aspect to pay attention to is track tension. One should aim to observe two dips between the drive sprocket and the idlers. A string can be drawn from the top to the bottom, ensuring that there is about one inch of space between the grouser bar and the string to indicate proper tightening. Additionally, check the chrome plating for maximum stretch; exceeding the maximum stretch will result in wear on all iron components.
For operators, it is essential to avoid operating the machine at high speeds in either forward or reverse. Such practices lead to premature wear on bushings and sprockets. If the tracks are too taut, wear will accelerate. It is critical to maintain a slight amount of slack in the tracks to allow for movement between the iron components, thereby preventing excessive wear.
One of the most important factors in prolonging the lifespan of a bulldozer's undercarriage is maintaining its cleanliness. Removing all debris from within the links and from the frame allows the components to move freely and promotes longer component life.