Fault Phenomenon: Shantui SD16 dozer transmission oil temperature high, but fan speed remains very low, not increasing with temperature.

Troubleshooting Process:
– Checked coupler: silicone coupler leaking or temperature-sensing spring failed.
– Checked fan: fan blades intact.
– Checked belt: belt tension normal.
– Measured temperature difference: small temperature difference across cooler.

Root Cause: The silicone coupler for the transmission oil cooler fan failed, unable to automatically adjust fan speed based on oil temperature, resulting in insufficient cooling.

Required Parts: Replace fan silicone coupler assembly.