Fault Phenomenon: Caterpillar 966 wheel loader severe body shudder when engaging forward or reverse gear.

Troubleshooting Process:
– Checked accumulator: transmission accumulator nitrogen leaked or bladder ruptured.
– Checked pressure reducing valve: transmission control valve pressure reduction unstable.
– Checked oil quality: severely contaminated transmission fluid.
– Checked solenoid valve: electronic proportional valve signal fluctuation.

Root Cause: The transmission shift accumulator bladder ruptured, losing its cushioning effect, causing the clutch to engage too quickly and produce shock.

Required Parts: Replace transmission accumulator bladder or assembly, recharge with nitrogen.