Article by Tim Nenne,
Undercarriage Market Professional, Caterpillar, Inc.
Southern loggers tend to favor wheel-type machines in the woods, but in some areas track cutters get the job done. You’ll also find bulldozers and excavators in many loggers’ equipment stables. If you have track machines in your operation and you’re working hard to keep expenses in line, you need to know that the undercarriage can account for up to 50%, on average, of your costs to maintain these machines.
Proper operating and maintenance procedures can help you hold the line on operating costs on your track machines. Here are a few suggestions:
Maintain track tension daily—Improperly adjusted tracks are the primary reason for increased wear and reduced life and performance of an undercarriage. When tracks are too tight, the contact loads between the components go up substantially (see graph). These higher loads increase the rate at which components wear. Tight tracks also increase the risk of dry joints, create stress on drive train components and increase fuel use. If tracks are too loose, they can drag on top of the roller frames, damaging the roller frame structure and causing premature wear on the links.
When you move to a new site or start a new application, run the machine for an hour and then adjust the track tension to the manufacturer’s specifications. When conditions change, re-check the tension and adjust as needed. For example, rain may change the track tension due to packing of debris within the undercarriage components.
Travel with idlers in front—Traveling is one of the most difficult applications for a track machine. You can minimize the wear by always traveling with the idlers in front. The idler has a spring assembly that acts as a shock absorber and chain tensioner. When tracking where there are stumps and rocks, traveling forward helps reduce undercarriage wear and increases final drive and sprocket life. Traveling idler first also makes the ride smoother and minimizes wear on the chain.
Inspect daily—Your daily machine inspection should include key aspects of the undercarriage. Look for loose or missing bolts, oil leaks, unusual wear patterns, loose or bent shoes, debris stuck in the undercarriage, etc. The pads are the components most likely to come loose, so tap on each pad to ensure they are secure.
Clean carrier rollers daily—Even in a Southern winter, mud and debris can get packed around top rollers and freeze overnight. In the morning when you try to move the machine, the track may move but the rollers sometimes will not turn. Operating in this condition will eventually wear a flat spot on the rollers. It is very important that the top rollers are cleaned out at the end of every shift to prevent downtime. Also, mud and debris may freeze between the track bushings overnight. In the morning, use the boom to gently lift the machine and then slowly rotate the tracks. This will help clean the bushings and get the stiff tracks moving. Machines equipped with star top rollers help reduce mud in the track chain.
Exercise parked machines—If you’re parking your machine and the tracks have over 1,500 hours, exercise the tracks for a few minutes each month so the track joints don’t seize up.
Here are a few suggestions specifically pertaining to track feller-bunchers:
Avoid sharp turns—Try to avoid spinning the machine sharply in place to turn. This pivoting motion not only tears up the ground, it is very hard on track chain bushing life.
Take stumps head on—If you can’t avoid a stump with a track, take it straight on and line up the center of the stump with the center of the track. The bolts in the center hold the track pad to the chain; taking a stump on the edge puts a bending force on the track pad and the chain.
Minimize travel with loads—You can’t completely avoid traveling with a load in the head, but minimize this as much as possible because the extra weight puts more stress on your track chain.