CAT Swing Motor – 385C / 390 Excavators
This swing motor is a high-quality replacement component designed for CAT construction equipment. Manufactured to meet or exceed OEM specifications, it ensures reliable performance and long service life in demanding operating conditions.
Applications
CAT 385C and CAT 390 large excavators working in quarry, mining and heavy construction. The swing motor drives the rotation of the complete upper structure through the swing gearbox and swing circle, and is one of the most heavily loaded hydraulic components on the machine.
Machine Compatibility
- CAT 385C Excavator
- CAT 390 Excavator
We also supply swing motors, swing gearboxes and swing drives for other large excavator models. Send us your machine model and serial number and our sales team will confirm the exact configuration for your unit.
Technical Specifications
- Product Type: Swing Motor
- Quality: OEM specification
- Condition: New
Usage Notes
- Always confirm the machine model and serial number before ordering to receive the correct motor configuration.
- Never plug or restrict the case drain line.
- Engage the swing lock and relieve system pressure before any work on the swing circuit.
- After replacing the motor, check the swing gearbox oil for metal particles that indicate pinion damage.
Installation Guide
- Park the machine on level ground, engage the swing lock, stop the engine and relieve residual hydraulic pressure.
- Thoroughly clean the area around the swing motor and gearbox mounting flange.
- Mark and cap the main pressure, return and case drain lines immediately after disconnection.
- Remove the mounting bolts and carefully lift the swing motor off the gearbox input shaft.
- Install the new swing motor, aligning the output splines with the gearbox pinion without forcing.
- Use new O-rings and seals and tighten all mounting bolts to the specified torque values.
- Fill the motor housing with clean hydraulic oil and reconnect the case drain line first – a blocked drain over-pressurizes the motor and damages the shaft seal.
- Release the swing lock and slowly rotate the upper structure several times to bleed air from the circuit.
- Check the swing gear oil level, then verify smooth operation, correct swing speed and proper swing braking.
Reference Price Range
The reference price for this swing motor is approximately USD 2,500 – 7,000 per unit, depending on configuration, availability, core exchange and shipping destination. Contact our sales team for a precise quotation. Volume discounts are available for fleet operators and repair shops.
Maintenance Tips
- Check the swing gear oil level on schedule and replace it at the OEM-recommended interval.
- Keep the case drain line clear at all times; a restricted drain blows the motor shaft seal.
- Grease the swing circle and swing pinion according to the machine lubrication chart.
- Watch for swing drift, jerky rotation or unusual noise and repair promptly to avoid gearbox damage.
- Do not shock-load the swing brake – always come to a complete stop before changing swing direction.
Warranty
All products supplied by us are covered by a 12-month warranty against manufacturing defects in materials and workmanship.
Shipping and Delivery
In-stock items ship within 24-48 hours via express freight (DHL, FedEx, or UPS). Standard delivery time is 5-10 business days worldwide.
Why Choose Our Products?
- Direct OEM replacement with guaranteed fitment and performance
- Rigorous quality testing before shipment
- Competitive pricing with factory-direct supply chain
- Technical support available for installation and troubleshooting
- Proven reliability with thousands of units supplied worldwide
