Posūkio reduktorius Eaton RB238-61280 mini ekskavatoriaus Kubota KX41-3 U17 U17-3a U15 U15-3

1. Product Identification
Component: Hydraulic Swing Motor Device Assembly

Manufacturer Model Numbers: Eaton 104-6473-005 / 104-6490-005

Kubota OEM Part Numbers: RG138-61280, RB238-61280

Machine Compatibility:

Kubota KX41-3

Kubota U17

Kubota U17-3a

Kubota U15

Kubota U15-3

Condition: Brand New Original / OEM Specification Equivalent

2. Technical Specifications
Type: Geroler / Disc Valve Hydraulic Motor (Eaton 2000 Series Platform Architecture)

System Output: Factory-matched displacement and rotational torque settings designed for Kubota 1.5 to 1.7-ton zero-tail-swing mini excavators.

Integrated Valve Network: Built-in dual-cushion swing relief valves to eliminate hydraulic shock and control deceleration drift.

Interface Mount: Standard 4-bolt flange with an integrated output spline shaft configured to mesh directly with the factory slew ring reduction gears.

3. Critical Installation Requirements
Motor Case Priming (Mandatory)
Before starting the excavator engine or operating the swing circuit, manually fill the swing motor housing with clean, fresh hydraulic oil through the highest available case drain port. Running the motor bone-dry—even for a few seconds—will score the internal wear plates and lead to immediate component bypass.

Verify Case Drain Line Clearance
Thoroughly inspect the case drain line running back to the hydraulic reservoir. Ensure there are no sharp bends, kinks, or internal blockages. Any flow restriction in this circuit creates immense housing backpressure, which will instantly blow out the main shaft seal.

Gear Pinion & Slew Ring Lubrication
Ensure the mounting surface on the excavator chassis is completely clean. Apply a liberal, heavy layer of premium quality lithium gear grease to the motor's output spline pinion and the main swing bearing ring gear teeth during installation.

Fluid & Circuit Decontamination
If the previous motor failed mechanically and left metal fragments in the oil, you must drain the hydraulic tank, flush the control valve's swing circuit lines, and clean out the oil cooler lines. Residual abrasive particles will rapidly score and destroy the new assembly.

4. Frequently Asked Questions (FAQ)
Q: What is the difference between part numbers RG138-61280 and RB238-61280?
A: These numbers represent engineering supersessions and production updates used by Kubota across the U15 and U17 model generations (such as transition to the Dash-3a series). Both tie back to the foundational Eaton 104-6473-005 / 104-6490-005 motor platform, meaning they maintain identical mounting dimensions and performance parameters.

Q: My mini excavator rotates smoothly but drifts or wanders when I try to work on a slope. Will this solve the problem?
A: Yes. Overtravel, wandering, or slow drifting when the joystick is in neutral typically indicates worn internal dual-cushion relief valves or weak return springs within the motor housing. Replacing the complete device restores exact stopping and holding power.

Q: Does this swing motor come ready to install?
A: Yes. Our brand-new assemblies come complete with the porting blocks, factory-set relief valves, and internal dynamic components fully assembled and pre-tested for plug-and-play installation.

5. Shipping & Logistics
Packaging: Thoroughly treated with rust-inhibiting storage oil, fitted with heavy-duty port plugs to prevent dirt ingress, and packed securely inside an export-safe protective box.

Transit Time: Global express air freight via DHL/FedEx/UPS typically delivers within 3 to 7 business days directly to your workshop or site.