EX60-1 EX60-2 4188099 4255146 Excavator Slewing Swing Motor Assembly Compatible with Hitachi

The EX60-1 / EX60-2 Slewing Swing Motor Assembly (OEM Part # 4188099 / 4255146 / M2X63 / MSG-27P) combines both the high-torque hydraulic axial piston motor and the planetary swing reduction gearbox designed for 6-ton class compact excavators.

• Factory Wholesale Price: $1,200 – $2,400 USD (Direct manufacturer pricing — Save up to 50% vs regional dealer markups)
• MOQ & Bulk Discount: 1 Unit (Tiered wholesale discounts available for batch container orders)
• Lead Time: 1–3 business days (Large factory stock ready for immediate worldwide dispatch)
• Warranty: 12 Months full replacement warranty with 100% bench test video proof

Engineered to deliver smooth rotation torque and rapid anti-rebound swing control under continuous field operations:

• Urban Pipe Trenching & Utility Work: Precise positioning control during narrow ditch digging and municipal pipe laying.
• Landscaping & Small Earthmoving: Rapid 360-degree loading cycles when moving soil and gravel into dump trucks.
• Building Demolition & Concrete Breaking: Heavy-duty casing built to withstand intense side-impact loads and breaker tool vibration.
• Farm & Agriculture Drainage Clearing: Reinforced shaft seals prevent mud, water, and grit contamination in muddy environments.

If your 6-ton excavator is experiencing swing mechanism failure, check the diagnostic guide below:

• Fault 1: Weak Swing Power or Slow Rotation (回转无力/动作发慢)
  Root Cause: Excessive wear on the motor cylinder block valve plate or internal friction brake plate degradation.
  Solution: Replace worn rotary group parts or install a complete drop-in EX60-1 slewing motor assembly (OEM 4188099).
• Fault 2: Severe Shaking, Jerking or Abnormal Metallic Noise During Rotation (抖动异响/回转卡顿)
  Root Cause: Broken teeth in planetary gears, worn drive shaft bearings, or pitted swing ring pinion teeth.
  Solution: Inspect reduction gear teeth and replace drive shaft bearings immediately to prevent complete gearbox lockup.
• Fault 3: Hydraulic Oil Leakage From Main Drive Shaft Seal (回转轴封漏油)
  Root Cause: Clogged casing drain line causing excessive internal housing pressure, blowing out the drive shaft seal.
  Solution: Clear drain circuit line and install a high-pressure skeleton oil seal group.
• Fault 4: Swing Drift / Auto-Slewing Slip When Parked on an Incline (斜坡停车自动溜车)
  Root Cause: Mechanical parking brake disc wear or sticky brake solenoid valve spool failing to seat properly.
  Solution: Replace brake disc plates and clean/recalibrate the swing parking brake solenoid valve.
• Fault 5: High Operating Oil Temperature & Torque Loss After 1 Hour (高温掉压)
  Root Cause: Thermal expansion oil bypass caused by score marks on the distributor valve face.
  Solution: Lap valve plate face or replace complete hydraulic motor section.

Explore our factory-direct replacement components compatible with major global excavator brands:

Q1: How do I verify if this slewing motor fits my EX60-1 excavator?
A: Check your original swing motor tag for OEM part numbers 4188099, 4255146, or M2X63 stamp. You can also send us your machine serial number for instant fitment check.
Q2: My EX60-2 excavator drifts when digging on a slope. Will replacing this swing motor solve the issue?
A: Yes, swing drift on slopes is caused by worn brake discs inside the motor gearbox or a failing brake solenoid valve. Installing our complete EX60 motor assembly restores firm parking brake holding power.
Q3: Is this EX60-1 slewing motor bench tested before shipment?
A: Yes, every single EX60 swing motor undergoes a rigorous factory bench pressure test up to 250 Bar and volumetric efficiency check. A live test video is provided before dispatch.