Fault Phenomenon: TCM FD30 diesel forklift transmission automatically jumps from second gear to neutral while driving, power transmission interrupted, accompanied by gear grinding noise.

Troubleshooting Process:
– Checked transmission oil level: level normal.
– Checked shift linkage: excessive linkage clearance.
– Checked transmission gears: gear wear normal.
– Checked transmission bearings: bearings loose.

Root Cause: Worn transmission shift fork or loose bearings cause unstable gear meshing.

Required Parts: Transmission shift fork or bearing repair kit.