Fault Phenomenon: XCMG XKT mining truck a tire becomes loose; inspection reveals multiple wheel lug bolts broken.

Troubleshooting Process:
– Checked bolts: fracture surface shows fatigue characteristics.
– Checked torque: bolts not tightened to specified torque or uneven force distribution.
– Checked wheel hub: wheel hub bolt holes worn and deformed.
– Checked material: insufficient bolt strength grade.

Root Cause: The wheel lug bolts fatigued and broke due to insufficient or uneven initial tightening torque, causing them to bear shear and alternating stresses during driving.

Required Parts: Replace full set of high-strength wheel lug bolts, and tighten to specified torque and sequence.