Caterpillar 336E Swing Motor Assembly – M5X180 (OEM 349-4380)

Tatan Machinery supplies 100% Brand New M5X180 hydraulic swing motor assemblies (OEM part numbers: 349-4380 / 200-3373, interchangeable with 334-9979 / 587-4947 / 204-2679) for Caterpillar 336E and 336E L heavy crawler excavators. Powering the upper carriage rotation through the planetary swing reduction gearbox, this high-pressure axial piston motor features an integrated multi-disc wet parking brake, anti-reverse shock damping valves, and dual port relief cartridges. Backed by our 12-Month Comprehensive Replacement Warranty, each complete assembly is factory bench-tested to verify brake release pressure, slew torque consistency, and zero housing bypass leakage.

Supplier Information & Build Status

When to Replace the Swing Motor on CAT 336E: Diagnostic Criteria

Continuous swing cycles with heavy 36-ton mass inertia create extreme thermal and shock loads on the M5X180 motor. In quarrying and mass loading, replace the complete assembly under these severe symptoms:

• Upper Structure Slew Drift on Inclines: When working or parking on slopes with the swing joystick in neutral, the excavator cab slowly rotates. This indicates severe friction disc wear inside the mechanical brake pack or worn motor barrel valve plates leaking past the seals.
• Violent Slew Stop Shock & Rebound (Anti-Reaction Valve Failure): When letting go of the swing joystick, the excavator shudders violently, bounces back, or makes loud metallic clunking noises. The internal anti-reaction shock relief valves are scored or jammed with debris.
• Loss of Swing Acceleration & Extreme Cavitation Noise: The excavator turns sluggishly when swinging into the truck. High case-drain oil flow dumping into the tank causes loud groaning noises, indicating swashplate galling and brass slipper shoe wear.
• External Hydraulic Oil Leakage into Gearbox: Blown motor output shaft seals allowing high-pressure hydraulic oil into the planetary swing reduction gearbox, overfilling the gear oil cavity and blowing out the gearbox top dipstick/breather.

Workshop Bench Testing & 12-Month Warranty Guarantee

Every 100% Brand New M5X180 swing motor supplied by Tatan Machinery comes backed by a 12-Month Comprehensive Replacement Warranty. Before crate packaging, our hydraulic engineers execute a 5-point dynamic bench test protocol:

1. Slew Relief Pressure Calibration: Port overload relief cartridges calibrated to exact Cat 336E factory specifications (26.5 MPa / 28.0 MPa shock peak) on our high-torque hydraulic motor test stand.
2. Mechanical Parking Brake Torque & Hold Test: Static torque test verifying the multi-disc wet brake securely locks rotation up to 967 N·m, and releases completely at 0.6 MPa pilot pressure.
3. Anti-Reaction Valve Damping Verification: Measuring brake switching valve opening pressure and 5–8 second delay curve to guarantee buttery-smooth slew stopping without jerky hydraulic shock.
4. Internal Case Drain Leakage Verification: Continuous testing under full operating temperature (55°C) to ensure internal slippage is below OEM limits, preventing heat buildup.
5. Shaft Spline Concentricity & Seal Integrity: Dial indicator check on the output drive spline matched for the CAT 336E swing reduction gearbox input gear.

Export Heavy-Duty Packaging Process

Precision motor rotating groups and polished valve plates require complete moisture and impact protection during international transit:

• 100% Sealed Metal Port Caps: Main working ports (flanged SAE), brake release pilot port, and case drain port fitted with heavy-duty metal blanking plugs.
• Anti-Corrosion VCI Wrapping: Bare output shaft splines and unpainted mounting flanges are coated with thick anti-rust grease and vacuum-sealed in VCI protective foil.
• Rigid Timber Base Skid Bolting: The motor is anchored upright through its mounting pilot flange into custom-cut solid wood framing inside the crate.
• Solid ISPM 15 Export Wooden Box: Fumigation-free plywood box reinforced with multi-banded high-tensile steel strapping.

Actual sealed port caps and heavy-duty crating for M5X180 swing motor

Global Shipping & Customs Documentation

Direct international dispatch tailored for commercial contractors and parts distributors:

• Emergency Machine Down Air Cargo: Fast air express via DHL Aviation, FedEx Freight, or international airlines within 3–7 business days.
• Consolidated Ocean Sea Freight (LCL / FCL): Direct containerized shipping to worldwide commercial ports.
• Clean Customs Clearance Paperwork: Commercial Invoices with correct HS Code (8412.29 – Hydraulic Motors), Packing Lists, and Certificates of Origin for tariff optimization.

Container loading and air freight dispatch supported by global logistics partners

Critical Installation Guidelines (CAT 336E Swing Motor Technician Checklist)

To prevent instant failure and protect your 12-month warranty, technicians MUST adhere to these critical procedures:

1. MANDATORY: Pre-Fill Motor Casing with Hydraulic Oil: Before starting the machine, remove the top case-drain plug and fill the motor casing completely with clean ISO VG 46 hydraulic oil. Running a new swing motor dry for even 3 seconds will instantly seize the rotating cylinder barrel and brass slipper shoes!
2. Inspect Planetary Swing Gearbox Oil & Level: Before bolting the motor onto the reduction gearbox, check the gear oil (Cat FDAO / SAE 80W-90) inside the gearbox. If the old motor leaked oil into the gearbox, drain and refill the gearbox to the proper dipstick level.
3. Verify Parking Brake Release Pressure: Connect a pressure gauge to the brake release pilot port. Confirm the pilot signal reaches at least 3.9 MPa when moving the swing joystick, ensuring the wet brake discs release fully without dragging.
4. Air-Bleed the Slew Relief Manifold: Loosen air bleed plugs on the top relief valve block during low-idle rotation until pure oil emerges without air bubbles. Air pockets cause severe hydraulic hammering.
5. Check Output Spline Engagement: Clean the female input splines of the swing gearbox. Ensure the motor output shaft splines slide in smoothly by hand; never draw the motor down using the mounting bolts!

Buyer Frequently Asked Questions (Purchasing FAQ)

🔗 Frequently Purchased Together with CAT 336E Swing Motor:

• DIESEL ENGINE:
  Caterpillar C9.3 Diesel Engine Assembly for CAT 336E (379-3736)
  Remanufactured
• MAIN VALVE:
  KMX32NB 428-2749 Main Control Valve Assembly for Caterpillar 336E
  100% Brand New
• HYDRAULIC PUMP:
  SBS140 Main Hydraulic Pump Assembly for Caterpillar 336E
  100% Brand New
• BRAND CATALOG:
  View All Caterpillar Excavator & Heavy Equipment Parts Collection

Get Wholesale Factory Quote for M5X180 349-4380 Swing Motor

Looking for direct factory pricing, stock availability, or 12-month warranty terms for Cat 336E swing motors? Contact senior specialist Gavin now!

💡 Fast Quote: Send your machine serial number or current motor nameplate photos for an accurate match within 10 minutes!