The Harsh Life of Forestry Work Requires Regular Maintenance
Few attachments undergo the harsh operating conditions of a mulching head. Between the abrasive work, the debris-filled environment and often hot weather, these attachments have to be built tough to handle all the abuse. But no matter how tough they may be, all mulching heads need regular maintenance to operate at peak performance and live a long service life. Of course, each manufacturer may offer different maintenance recommendations, so it’s important to read the operator’s manual for specific instructions and service schedules. Nonetheless, here are several universal tips that apply to most any mulching head.
One of the most basic maintenance recommendations for a mulching head is to keep it clean of debris. Check the unit before and after use, and keep a close eye during operation as well. Even though some branches, sticks or other small debris hung up in the housing may not seem to affect performance, they’re likely wasting precious horsepower by restricting the rotational spin of the rotor. As a result, less horsepower is available for the actual job, more fuel is consumed and excessive heat is generated in the hydraulic system. Equally important is keeping the power unit (track loader or tractor) free of debris. Pay special attention to the radiator, oil cooler, exhaust and other areas that could cause overheating or perhaps even start a fire.
When cleaning the attachment and power unit, inspect the entire machine for any visible oil leaks, worn hydraulic hoses or bad wiring that could fail during operation. Also, check for loose hardware, particularly the knife bolts. It’s not unusual for the vibration of a mulching head to rattle some bolts loose, so be sure to tighten them regularly. Operating with knife/tooth bolts loose can result in permanent damage to the welded holder, causing costly repair and downtime.
Every day it’s also important to check the cutting teeth to ensure optimal performance. If you’re using carbide or carbide-tipped teeth, then no sharpening is necessary. Simply replace the teeth as they wear. Always be sure to replace the teeth in pairs (the damaged or worn tooth as well as the tooth on the opposite side of the rotor) to keep the rotor properly balanced. If the mulching head has hardened steel blades, which have become more popular in recent years, then the blades will need to be checked daily and sharpened often to maintain their superior cutting performance. If the blades are reversible, the operator can alternate cutting edges to reduce sharpening frequency.
Some mulching heads are designed so the blades can either be sharpened while attached or detached from the machine. If sharpening them on the machine, a ratchet strap may be used to keep the rotor from turning. Using a hand grinder or other machine shop equipment, lightly grind each blade, being careful not to generate excess heat by grinding one blade too long, which can ruin its heat-treated properties. If the blade’s coloring changes to blue or brown while sharpening, it means the temper has been removed, and the blade will no longer hold its cutting edge. Additionally, sharpen each blade equally to help maintain rotor balance. If the blades were removed from the rotor for sharpening, return each one to its original location for balancing purposes.
Lubrication is another critical maintenance item often requiring attention every eight hours. It’s ideal to grease the rotor bearings at the end of the day when the bearings are warm, rather than in the morning. Generally, rotor bearings can’t be over greased, so apply grease until grease starts to purge from the bearing. In addition to the rotor bearings, the belt tensioner must also be greased but only about every 50 hours of operation. Check the owner’s manual for the proper amount of grease to apply. If these zerks are over lubricated, the grease may transfer to the belt, causing it to slip. As a result, the operator could experience loss of rotor rpm and power. Greasing the belt tensioner can be a great opportunity to also check the belt tension, which is typically recommended every 100 hours.
With the side cover already off, a person can quickly measure the spring tension and adjust as needed. Recommendations may vary by manufacturer, so check the operator’s manual for detailed instructions.
Pre- and Post-Season
When putting a mulching head in storage for the winter, be sure to clean it thoroughly and lubricate all parts on the machine. Replace all worn or damaged parts, and touch up any exposed metal with paint to help prevent rust. Finally, relax the drive belt tension, lower the support stands and put the unit away in a clean, dry area. If desired, the push bar can also be moved up to storage position. At the beginning of the next season, check again that all components are well greased and that no parts are damaged. Tighten all bolts, nuts and screws, and then adjust the drive belt to the proper tension. After that, install the mulching head to a power unit to test it before getting started on the job. Make sure the rotor rotates the proper direction, as illustrated on the machine. If it starts spinning backward, reverse the hydraulic couplers on the power unit. Furthermore, ensure the skids are adjusted to the desired height.
Even after routine service has been completed and the mulching head has been tested, don’t stop thinking about maintenance. When running the machine, keep in mind proper operating procedures to reduce the risk of maintenance issues down the road. For instance, do not mow areas that are littered with debris such as bottles, metal objects, rocks and wire, which can prematurely wear the cutting teeth or even damage the machine. Additionally, do not operate the mulching head above the rated rpm to avoid damage or safety concerns.
Finally, as always, keep safety in mind when operating mulching heads. Keep all body parts away from the machine when the power unit is on, and do not allow any people or animals within 300 ft of the work area. Additionally, be careful when lifting or tilting the mulching head, which increases the risk of flying debris. In the end, it doesn’t take a gear head to maintain a mulching head. It just takes discipline to keep the machine clean, the components greased and the blades sharpened. Ultimately, all the time spent on routine maintenance will likely be gained back through increased performance and reduced downtime.