161-0028-002 Eaton Char-Lynn VIS 40 Hydraulic Motor

Product Overview

161-0028-002 is a legacy hydraulic motor part number commonly cross-referenced in the aftermarket to Eaton Char-Lynn VIS Series motors. Related references supplied with this product include 161-0085-003, 161-0085-005 and 1610028002. Multiple market sources also cross-reference these numbers to ACD24A00AA128E1E and identify the assembly as a 400 cm³/rev Char-Lynn motor.

Eaton’s official VIS 40 documentation confirms that the 400 cm³/rev VIS 40 configuration provides:

• 357 rpm continuous speed
• 368 rpm intermittent speed
• 151 L/min continuous flow
• 170 L/min intermittent flow
• 1781 Nm continuous torque
• 1597 Nm intermittent torque
• 310 bar continuous differential pressure
• 345 bar intermittent differential pressure
• 380 bar peak differential pressure

The VIS 40 platform uses patented VIS Geroler technology, a three-moving-component architecture and a two-piece pre-loaded pressure balance plate. Eaton designed the motor for compact packaging, high horsepower density and reliable low-speed high-torque performance.

An important sourcing note is that the Eaton VIS 40 official catalog uses 168-, 177- and 180-series product-number prefixes, while the 161-series numbers supplied here do not appear as complete product numbers in that catalog. Therefore, the complete original motor configuration should always be verified before claiming direct OEM interchangeability.

Technical Specifications

Official VIS 40 — 400 cm³/rev Data

• Original Brand: Eaton Char-Lynn
• Current Product Family: Danfoss Char-Lynn
• Series: VIS 40
• Technology: VIS Geroler
• Displacement: 400 cm³/rev
• Displacement: 24.4 in³/rev
• Maximum Continuous Speed: 357 rpm
• Maximum Intermittent Speed: 368 rpm
• Continuous Flow: 151 L/min / 40 GPM
• Intermittent Flow: 170 L/min / 45 GPM
• Continuous Torque: 1781 Nm / 15,760 lb-in
• Intermittent Torque: 1597 Nm / 14,137 lb-in
• Continuous Differential Pressure: 310 bar / 4500 psi
• Intermittent Differential Pressure: 345 bar / 5000 psi
• Peak Differential Pressure: 380 bar / 5500 psi
• Maximum Inlet Pressure: 400 bar / 5800 psi
• Maximum Case Pressure: 3.5 bar / 50 psi
• Minimum Back Pressure: 3.5 bar / 50 psi
• Maximum Back Pressure: 21 bar / 300 psi
• Intermittent Duty Rating: 10% of every minute
• Peak Duty Rating: 1% of every minute
• Recommended Fluid: Premium anti-wear hydraulic oil
• Minimum Viscosity: 70 SUS at operating temperature
• Recommended Operating Temperature: -34°C to 82°C / -30°F to 180°F
• Recommended Cleanliness: ISO 4406: 20/18/13
• Closed-Loop Case Drain: Required
• Closed-Loop Back-Pressure Relief Valve: Required
• Displacement Control: Fixed displacement
• Reference Weight for 400 cm³/rev Standard/Wheel Mount: 29.1 kg / 64.2 lb

Market Cross-Reference Information

• 161-0028-002
• 161-0085-003
• 161-0085-005
• 1610028002
• ACD24A00AA128E1E
• Common Product Family: Char-Lynn VIS hydraulic motor
• Reported Displacement: 400 cm³/rev
• Reported Shaft: 12-spline, approximately 38.4 mm diameter
• Reported Main Ports: 1-1/16 UNF
• Reported Case Drain: 9/16 UNF

The latter cross-reference specifications should be treated as fitment reference data, not as an Eaton-certified complete model-code definition.

Key Technical Advantages

Patented VIS Geroler Technology

Eaton’s VIS design represents an evolution of LSHT motor technology. The architecture uses three primary moving components: the Geroler star, drive and output shaft, helping create a compact motor package.

Two-Piece Pre-Loaded Pressure Balance Plate

The two-piece pre-loaded balance plate is designed to improve starting efficiency, reduce internal leakage and increase back-pressure capability. These characteristics are particularly relevant in low-speed, high-torque hydraulic applications.

High Torque from 400 cm³/rev Displacement

The 400 cm³/rev displacement produces substantial hydraulic torque at relatively low shaft speed. Eaton’s official data specifies 1781 Nm continuous torque for this displacement.

High Pressure Capability

The 400 cm³/rev VIS 40 configuration is rated at 310 bar continuous differential pressure, 345 bar intermittent and 380 bar peak. Eaton clearly separates continuous, intermittent and peak ratings, which is essential when applying the motor to real machine duty cycles.

Closed-Loop Optimized Architecture

Eaton states that VIS motors are primarily intended for closed-loop circuit applications. These applications require a case drain and an appropriate back-pressure relief arrangement, while case pressure must remain within the specified limit.

High Power Density

Eaton highlights the VIS 40 for its compact package, increased torque capability and high horsepower density. This allows high hydraulic output within machinery where installation space is limited.

Engineered Radial Load Capability

VIS 40 side-load curves are based on B10 bearing life at rated output torque and 100 rpm. Actual allowable radial load must be corrected for operating speed, making side-load analysis essential for sprocket, pulley and gear-driven applications.

Application Areas

Eaton identifies the following typical VIS 40 applications:

• Skid steer loaders
• Skid steer attachments
• Trenchers
• Grapples
• Rough terrain forklifts
• Forestry equipment
• Wood processing equipment
• Sawmills
• Chippers
• Snow removal equipment
• Harvesters
• Industrial processing machinery
• Material handling equipment
• Irrigation reels
• Augers
• Large turf care equipment
• Metal forming machinery
• Entertainment and amusement equipment

Aftermarket sources also associate 161-0028-002, 161-0085-003 and 161-0085-005 with Bobcat applications such as S175, S185 and 753. These application references should be independently checked against the machine serial number and original motor configuration before installation.

Expert Maintenance Tips

Always Install a Case Drain in Closed-Loop Applications

Eaton explicitly states that closed-loop VIS motors require a case drain. Without the drain, the internal drive spline may not receive adequate lubrication.

Keep Case Pressure Below the Specified Limit

The official maximum case pressure is 3.5 bar / 50 psi. Restricted drain lines, excessive return pressure or incorrect plumbing can increase case pressure and negatively affect seals and internal components.

Do Not Operate Continuously at Maximum Speed and Torque

Eaton specifically warns that maximum torque and maximum speed should not be applied simultaneously. Motor selection should therefore follow the actual torque-speed operating envelope rather than multiplying individual maximum values.

Perform a Controlled Break-In

Eaton recommends operating the motor for approximately one hour at 30% of rated pressure before applying full load, and the motor must be filled with hydraulic fluid before any load is applied.

Maintain Hydraulic Cleanliness

The Eaton specification recommends ISO 4406 cleanliness level 20/18/13 and premium anti-wear hydraulic oil with viscosity of at least 70 SUS at operating temperature.

Verify Radial Shaft Loading

Where the motor drives a sprocket, pulley or gear, evaluate the radial load together with load position, speed and bearing-life requirements. Eaton provides speed correction factors for the side-load curves.

Apply 100% Simulated Operating-Condition Testing

For replacement units associated with 161-0028-002 / 161-0085-003 / 161-0085-005, a professional QA program should verify:

• Operating pressure
• Flow rate
• CW/CCW rotation
• Output speed
• Starting performance
• Case-drain behavior
• External leakage
• Housing temperature rise
• Abnormal noise
• Mounting dimensions
• Shaft spline dimensions
• Hydraulic port configuration

This provides a stronger basis for dimensional, functional and operating-condition interchangeability than part-number matching alone.