Fault Phenomenon: Unicarriers UF25 diesel forklift when starting with heavy load, engine RPM increases but vehicle speed does not, burning smell detected.

Troubleshooting Process:
– Checked clutch pedal free play: excessive play.
– Checked clutch disc: friction disc severely worn.
– Checked pressure plate: pressure plate spring fatigued.
– Checked flywheel: flywheel surface burnt.

Root Cause: Excessive wear of the clutch disc or fatigue of the pressure plate springs causes insufficient clamping force.

Required Parts: Clutch kit (disc, pressure plate, release bearing).