88 HT25 - MAINTENANCE TRENCHER Check two upper and two lower bolts every 10 hours for looseness or wear. Torque as necessary to keep bolts and nuts tight. Check 4 bolts every 10 hours for looseness or wear. Torque as necessary to keep bolts and nuts tight. Attachment Mounting Bolts Check one bolt every 10 hours for looseness or wear. Torque as necessary to keep bolt and nut tight. Boom Mounting Bolts Personnel Restraint Bar p