Product Overview
The 161-0085-005 hydraulic motor is part of Eaton’s Char-Lynn® VIS 40 Series (Valve-In-Star) Low Speed High Torque (LSHT) gerotor hydraulic motors, representing a large-displacement option within the VIS Series. The VIS 40 Series features Valve-In-Star commutation technology and a Geroler® gearwheel set, with displacements ranging from 505 to 785 cm³/rev, maximum continuous flow of 151 L/min, maximum intermittent flow of 170 L/min, and maximum continuous pressure differential of 241 bar. The series delivers high starting torque and smooth low-speed operation, making it a core product in the Char-Lynn line for high-torque applications.
The 161-0085-005 corresponds to OEM reference code ACD24A00AA128E1E, with a displacement of approximately 776 cm³/rev (47.36 in³/rev). It features a 4-bolt SAE flange mounting (pilot Ø127mm, bolt circle Ø114.5mm), Ø38.4mm keyed shaft with 12 splines, 1-1/16 UNF main ports, 9/16 UNF case drain port, and weighs approximately 17.93 kg. This motor is primarily used for the travel drive system of Bobcat skid steer loaders (S175, S130, etc.) and serves as an interchange replacement for Eaton 161-0085-003.
This product is a drop-in interchange replacement for genuine Eaton Char-Lynn 161-0085-005 hydraulic motors. Mounting flange, shaft extension, port configurations, and case drain port location are dimensionally identical to OEM specifications, enabling direct replacement without hydraulic circuit or mounting modification. Every motor is subjected to 100% simulated actual-load testing before shipment, ensuring volumetric efficiency, output torque, and sealing performance meet OEM technical standards.
OEM Part Number Coverage:
Primary Model: 161-0085-005 (OEM Reference: ACD24A00AA128E1E)
Interchange Models: 161-0085-003, 161-0028-002, 177-0011-005
Compatible Machines: Bobcat S175, S130, S150, S160, S185, S205, S510 skid steer loaders
Cross-reference: Bobcat OEM 7499819, 6682034, 6671617
Technical Specifications (Bulleted List)
161-0085-005 Core Specifications:
Model Code: 161-0085-005
OEM Reference: ACD24A00AA128E1E
Series: Eaton Char-Lynn VIS 40 Series (Valve-In-Star)
Product Type: Low Speed High Torque gerotor hydraulic motor, Valve-In-Star design
Gearwheel Set Type: Geroler®
Geometric displacement: Approx. 776 cm³/rev (47.36 in³/rev)
Max continuous pressure differential: 241 bar (3500 PSI), VIS 40 Series continuous limit
Max intermittent pressure differential: 276 bar (4000 PSI), VIS 40 Series intermittent limit
Peak torque: Approx. 2600 Nm (23000 lb-in), VIS 40 Series same displacement class
Max continuous flow: 151 L/min (40 GPM), VIS 40 Series continuous limit
Max intermittent flow: 170 L/min (45 GPM), VIS 40 Series intermittent limit
Max continuous speed: Approx. 195 rpm (based on 776 cc/rev and 151 L/min)
Max intermittent speed: Approx. 220 rpm (based on 776 cc/rev and 170 L/min)
Control type: Fixed displacement, Valve-In-Star commutation
Mounting flange: 4-bolt SAE flange, pilot Ø127mm, bolt circle Ø114.5mm, hole Ø14mm
Shaft type: Ø38.4mm keyed shaft, 12 splines, shaft length 68mm
Main ports: 1-1/16 UNF thread (3 ports)
Case drain port: 9/16 UNF thread
Rotation: Bi-directional
Housing material: Cast iron
Weight: Approx. 17.93 kg
Dimensions: Overall length 212mm, flange diameter 141mm
Key Technical Advantages
1. Valve-In-Star Commutation Technology with High Volumetric Efficiency
The VIS 40 Series utilizes Char-Lynn’s patented Valve-In-Star commutation technology, integrating the valve within the center of the gearwheel set for short commutation paths and low pressure losses. Combined with the rolling engagement characteristics of the Geroler® gearwheel set, the motor maintains high volumetric efficiency across the full speed range, with a minimum stable speed of 5–10 rpm without crawling. This structure is particularly suitable for Bobcat skid steer loader travel drive applications requiring precise low-speed control.
2. Large Displacement with High Torque Output
The 161-0085-005 delivers up to 2600 Nm of peak torque at 776 cm³/rev displacement, with maximum continuous flow of 151 L/min, making it a representative high-torque model in the VIS 40 Series. The cast iron housing provides robust structural support, ensuring long-term reliable operation under heavy-duty skid steer loader travel conditions. This torque level is sufficient to drive heavy skid steer loaders under fully loaded conditions.
3. High Starting Torque with Smooth Operation
The rolling engagement characteristics of the Geroler gearwheel set provide high starting torque efficiency, with starting torque exceeding 80% of rated torque. The precision-machined Valve-In-Star commutation system ensures smooth torque output even at very low speeds, without crawling. This characteristic is critical for precise maneuvering and loaded starts of skid steer loaders in confined spaces.
4. OEM Interchangeability with Broad Compatibility
The 161-0085-005 features high interchangeability with models 161-0085-003 and 161-0028-002, with compatible mounting interfaces and performance parameters. This model is widely compatible with Bobcat S175, S130, S150, S160, S185, S205, and S510 skid steer loaders, allowing direct replacement of OEM motors. It is also compatible with Bobcat OEM part numbers 7499819 and 6682034, significantly reducing spare parts management complexity.
Application Areas
Skid Steer Loader Travel Drive (Core Application): Travel drive system for Bobcat S175, S130, S150, S160, S185, S205, S510 models; direct replacement for Bobcat OEM 7499819 and 6682034
Construction Equipment: Mini excavator travel drive, skid steer attachment drive
Agricultural Machinery: Harvester drive, baler drive, irrigation equipment drive
Material Handling: Conveyor drive drum, scissor lift drive
Municipal Vehicles: Street sweeper brush drive, snow removal equipment drive
Expert Maintenance Tips
Pre-Installation Preparation:
Clean all ports and mounting flanges with lint-free wipes or clean compressed air before installation. Verify O-ring integrity. The 161-0085-005 uses a 4-bolt SAE flange mounting (pilot Ø127mm, bolt circle Ø114.5mm) — confirm the flange specification matches the system before installation. Torque mounting bolts (M12, hole Ø14mm) in a diagonal sequence over 2–3 passes. After installation, manually rotate the output shaft to confirm free and smooth rotation without binding.
Case Drain Port Management:
The 161-0085-005 features a standard 9/16 UNF case drain port. Route the drain line separately back to the reservoir with the end submerged below the oil level. Drain line back pressure should not exceed 2 bar. Excessive back pressure will damage the shaft seal. If no drain line is available, confirm the motor is in standard configuration (internal drain).
Hydraulic Fluid Management:
Use anti-wear hydraulic oil with ISO VG 46 or ISO VG 68 viscosity grade. Maintain fluid cleanliness at ISO 18/16/13 or NAS Class 8 minimum. Operating temperature should not exceed 80°C continuous; short-term peak up to 90°C is acceptable. Replace hydraulic fluid after the first 50 operating hours, then every 500 operating hours or quarterly.
Spline Shaft Care:
The 161-0085-005 output shaft is a Ø38.4mm keyed shaft with 12 splines. Apply molybdenum disulfide (MoS₂) fortified grease to the spline area periodically to reduce fretting wear. Inspect spline teeth for abnormal wear or pitting; replace the motor if wear exceeds 5% of tooth thickness.
Periodic Inspection:
Check volumetric efficiency every 500 operating hours or quarterly. Test method: lock the output shaft at rated pressure and measure leakage flow. If leakage exceeds 10% of rated flow, internal wear has entered an accelerated phase — schedule service or replacement. Also inspect shaft seals for seepage and spline shaft for abnormal wear. For Bobcat skid steer loader applications, a comprehensive inspection and maintenance is recommended before each operating season.
