Applicable Systems
CX210 Excavator
Symptoms
Transmission overheating after 1 hour of load-and-carry.
Possible Causes
- Transmission oil cooler fins plugged with dust.
- Torque converter stall condition (repeated high-stall digging).
- Transmission oil degraded with low friction modifier.
Troubleshooting Steps
- Step 1: Blow out transmission cooler fins with compressed air.
Air flows freely; no blocked core tubes. - Step 2: Check torque converter outlet temperature.
Outlet ≤ 110°C under rated load; no > 120°C excursions. - Step 3: Test transmission oil viscosity and compare to new sample.
Viscosity within 10% of new oil at 40°C. - Step 4: Check for clutch material in oil drain sample.
No large friction particles; oil color brown not black.
How to Reset
Clean cooler; change to correct HY-TRAN fluid; train operator to avoid prolonged stall.
Common Replacement Parts
- Transmission Cooler 1542925C1: Transmission Cooler 1542925C1
- HY-TRAN Fluid 1542926C1: HY-TRAN Fluid 1542926C1
Frequently Asked Questions
- Q: What is HY-TRAN?
Case proprietary transmission/hydraulic fluid with specific friction characteristics.
- Q: Can prolonged stall damage torque converter?
Yes, overheating destroys converter lining and seals.
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Source: Case 621G Transmission Manual
Category: Heavy Equipment
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