Pit & Quarry, December 2013

recommendation for your application and loads carried Always use sealing valve caps which have a sealing washer to retain tire pressure even when the valve core is partially open owing to dirt infiltration Tire changes Deflate the inner and outer tires of a dual fitment before removing any rim fixture from the hub of the vehicle Damage to the inner wheel assembly could cause injury when the outer is removed by releasing pent up energy that could dangerously propel wheel parts Avoid lifting tires through the center with a crane hook This can damage the critical bead area Instead lift the tire under the tread by using flat straps Flat straps are recommended over steel slings or chains because they are less likely to cause cuts or abrasions Avoid mixing tires on your vehicle such as normal tread depth with deep tread depth or a bias ply tire with a radial Using two different types of tires could damage the vehicles internal components because the tires do not work together to provide the same rolling circumference traction or handling performance Precautions Never weld or apply heat to a wheel or wheel parts Due to the potential hazardous nature of tire fires any wheel work should be done with the tires dismounted and removed from the wheel rim If a wheel requires repair it should be inspected and repaired by the wheel manufacturer Never operate a vehicle that has a flat or near flat tire damaged or distorted rims or wheels missing bolts or cracked studs Safety is key When not in use store tires in a cool dry place away from direct sunlight to avoid premature aging Prevent exposure to ozone sources such as sun arc welders and mercury vapor light bulbs as well as ultraviolet rays and inclement weather Store tires standing upright on the tread but supported to Maintain your tracks BY MITCH PELTOMAA Daily maintenance checklists for most tracked equipment generally include preshift inspections of the tracks themselves and the track gearbox Operators who ignore these inspections are tempting fate Depending on the type of failure it could take four to eight hours to fix a broken track and up to two days to remedy a final drive failure if the parts are handy Even worse ignoring damage to a track gearbox can run from 15000 for small machines up to 60000 or more for larger machines with associated costs and profit loss for two days labor and downtime The typical crawler rigs pre shift inspection includes track and track gearbox checks similar to those described below Check track tension Monitor track sag A track that is too tight increases the wear on both the front idle wheel and sprockets of the final driver If its too loose the track could fall off damaging the lower rollers and bushings Adjust them to measurements prescribed in the manual This usually involves putting the rig up on lifts and gauging the distance between two reference points Investigate unusual noises such as grinding and popping Be alert to any high whining noise which could indicate insufficient oil Torque bolts nuts Use a common torque wrench to set bolt nut tension Correct bolt torque is generally 420 ft lb 50 ft lb but always check the manufacturers recommendations This secures them as tightly as possible without threat of having them break under normal operational stresses Track pads can fall off or break the track rail if nuts are too loose Final drives can become loose and leak oil leading to environmental issues and ultimately partial seizure Maintain oil levels Keep oil levels to owners manual specifications to prevent damage and to extend useful life Service the oil on schedule often prescribed for every 250 hours and immediately upon discovering any leak Mitch Peltomaa is national service manager CMT store operation Atlas Copco Construction Mining Technique USA avoid injury or death from falling tires and avoid stacking Training Establish a training program for the machine operators to ensure they are properly trained This training should include visual tire inspection avoiding damage causing obstacles when operating equipment reporting obstacles that need to be removed from the site or repaired and using the proper operating speeds in corners or grades Following these simple steps will help productivity and add significant savings to the bottom line by reducing tire costs and ensuring safe operation P Q Steve White is market segment manager for Michelin Earthmover Tires EQUIPMENT FOCUS MAINTENANCE 42 PIT QUARRY December 2013 www pitandquarry com