Caterpillar Turbochargers for D6D Dozer, 320C Excavator | Inconel | Wholesale

Technical Q&A: Caterpillar Turbochargers

What causes Turbo Whining Noise and Shaft Seizure? (Tier 2 – Service Manuals)

Symptom: A loud, high-pitched whining noise (like a dentist’s drill) under acceleration, often followed by a sudden loss of power and heavy smoke. Diagnosis: This indicates the turbine or compressor wheel is contacting the housing due to excessive bearing wear. If ignored, the shaft will seize completely. This is usually caused by oil starvation or oil contamination (dirt/metal particles scoring the bearings). Solution: You must replace the turbocharger. Our VSR-balanced replacement units restore smooth, quiet operation. Crucially, you must resolve the underlying oil supply issue.

Why do Turbine Housing Cracks occur? (Tier 2 – Technical Documentation)

Diagnosis: Turbine housings, especially near the wastegate port or volute divider, are subjected to extreme thermal cycling (heating up to 900°C and cooling rapidly). “Heat soak cracking” happens when a heavy-duty machine (like a dozer or loader) is shut down immediately after a hard pull without allowing the turbo to idle and cool down. This rapid cooling fractures the cast iron. Solution: Our replacement turbos use high-nickel ductile iron housings for superior thermal fatigue resistance. Always implement a 3-5 minute idle cool-down procedure before shutting off the engine.

What is the most critical step when installing a new CAT turbo? (Tier 1 – CAT SIS)

Answer: Ensuring a clean, unrestricted oil supply and “oil priming” the turbo. Solution: Never reuse the old oil feed lines; they are often restricted by coked oil. Replace the oil feed line, change the engine oil and filter, and meticulously clean the mounting area. Before starting the engine, fill the turbo’s oil inlet with clean oil and manually spin the compressor wheel. Finally, crank the engine without starting it to build oil pressure in the new turbo bearing housing.

Is the CAT 320C turbo the same as the Mitsubishi TD06? (Tier 1 – CAT SIS)

Answer: Yes. The CAT 320C excavator uses the 3066 engine, which is structurally based on the Mitsubishi S6K. The OEM turbocharger for this application is frequently a Mitsubishi TD06 (e.g., cross-reference 49179-02340). We supply exact-spec TD06 replacements that bolt directly onto the 3066/S6K exhaust manifold, ensuring factory-correct boost delivery.