ADULT SECTION Maintenance Hi-Fax Replacement The 120 XC SP uses XTRA Lite style Hi-Fax. When any area of the Hi-Fax is worn to 7/16 (1.1 cm), it should be replaced. This will save wear on other vital components. The slide rail is designed to operate in conditions with adequate snow cover to provide sufficient lubrication. Excessive wear may be due to improper alignment, improper track adjustment or machine operation on surfaces without snow. Take the machine to your dealer for Hi-fax replacement. Hi Fax Wear Limit 7/16 (1.1 cm) XTRA Lite 72