It’s important to know when and how to properly recognise and replace the worn parts of your bulldozer. In the following article, you will learn how to recognise the wear patterns.
Track Link Wear:
Bulldozer track links wear on the bush surface and rail surface, as these chains are oil-filled the pitch should never change, unlike excavator chains.
- Bush diameter is one measurement that defines the wear factor, a specific measurement of the surface diameter defines when the chain is 100% worn out. This measurement varies between bulldozer types and sizes, please give us a call with this measurement and we can advise you of the life percentage left in the chain.
- Another measurement for wear is the rail height and it depends on the terrain and soil type as to which will wear first, the rail or bush. This measurement also varies between bulldozer types and sizes, please give us a call with this measurement and we can advise you of the life percentage left in the chain.
- Failure in loss of oil in links can occur in poor quality chains or if the machine is fitted with over width shoes for working conditions. This must be repaired immediately, or links and segments will be destroyed quickly. If this occurs in more than one link it may be more cost-effective to replace the whole chain.
- Cracked bushes can also occur also found in poor quality chains or chains not tensioned correctly, the oil will be lost, and chains will be destroyed quickly. Replace chains.
- Recommended not to fit new chains on rollers over 50% worn as the wearing surface will not be matching. This will increase rail wear on new chains.
Track Shoe Wear:
Shoes need to be replaced if the grouser or lugs are worn down when the machine has lost the desired traction. Larger machines can be effective to re lug, Caterpillar D6 size or down is more cost-effective to replace the shoes. If the shoes on your bulldozer are bending or cracking, it may be because they are too wide for the application or that they have worn out.
Roller Wear:
- Top and Bottom rollers wear on the running surface which reduces the diameter of the roller, a specific measurement of the running surface diameter defines when the roller is 100% run out. This measurement varies between bulldozer types and sizes, please give us a call and we can provide what measurement is required based on your dozer.
- The flanges wear if you are doing a lot of hillside work and turning excessively. Can also be increased significantly if track guards are not fitted and maintained to the right tolerance.
- Flat spots on the rollers are caused by the packing of material around the roller preventing it from turning or seizing of bearing. Regular cleaning prevents packing. Replace roller as continual use will increase wear on rails.
Link Wear:
- Track links wear on the idler running surface. A specified measurement from the centre rib to the running surface defines when the idler is 100% worn out. This measurement varies between bulldozer types and sizes, please give us a call and we can provide what measurement is required based on your dozer.
- If the sides of the grousers (centre rib) show signs of side wear, or the idler rubs against the side of the frame, then the track link is not in line with the idler. This may be caused by a cracked frame, worn mounting arms, worn slide in the frame, a broken axle, or a defective tension device. Excessive turning can also cause centre rib wear.
- If the bearing is defective and has lost oil, the idler will need replacing immediately before there is further damage to any other components.
- Wear on the top of centre rib is caused by bush contact if excessive wear or soil compaction in frame behind idler.
Segment Groups:
- Chips or wear in outer corners of teeth are caused by high impact conditions, misalignment of chains or too high track tension.
- Another common wear pattern for sprockets and segments is lateral wear. This is caused by (among others) worn chain guides, a twisted undercarriage, or poor guiding of the front idler. Can also be caused by the filtration of hard materials between the bushings and the sprockets, or by incorrect alignment.
- Sometimes the machine’s sprockets or segments are sharp, but the track links appear to be in reasonable condition. We are frequently asked whether the sprockets still need to be changed. The only reason why a sprocket becomes sharp is through the chain’s increased pitch. An increase in pitch creates more play between the pin and the bushing. As a result, the chain’s bushing no longer runs in line with the hollow part of the sprocket. This causes wear on the sprockets and the points become sharp. If replacing very worn sprockets without replacing the chains the bushes on the chain will load up the points of the teeth and will cause banging or jumping of the chain damaging the drive motors, sprockets, and chains. Same when replacing new chains always replace with new sprockets.
- You can get increased life from your chains if you replace the segments before the end of the chain life cycle; that way the undercarriage can be used for a few hundred more hours. Only recommended if the pitch has not been extended or still a fully sealed chain.