MAINTENANCE 4.12 EVERY 1000 OPERATING HOURS OR EVERY 6 MONTH High-Strength Bolt Connections (continued) Check tightening torque of the counterweight mounting bolts, illust. Z 21778 Reference No.: Qty. (1) Counterweight (2) Lifting eyes (3) Mounting bolts 16 * SW = Wrench size 399 Bolt size mm Grade SW * mm Tightening torque Nm M48 10.9 75 7500