The Chelsea 281 Series PTO showcases Parker Chelsea’s commitment to continuous innovation and engineering excellence. As an evolution of the top-selling Chelsea 280 Series, the 281 Series builds on proven performance with major design enhancements that deliver superior strength, durability, and vibration resistance.
There is also a version with an extended shaft, 281L Series, for Alison 3000 and 4000 transmissions.
Key Upgrades
- A ductile iron bearing cap that is 117% stronger than the previous design.
- An O-ring sealing configuration between the housing and bearing cap to improve clamp load and prevent leaks.
- Thicker steel clutch discs, increased by 80%, for greater durability and torque-handling capability.
Each of these advancements helps the Chelsea 281 Series withstand the increased vibration and stress generated by today’s and future high-performance engines—providing longer service life and unmatched reliability in demanding applications.
Technical Specifications
- Mounting Type: 10-Bolt
- Continuous Torque: 390 lb-ft (Check Application Pages for Actual Torque Ratings), 529 Nm (Check Application Pages for Actual Torque Ratings)
- Shift Type: PowerShift (Hydraulic), Hydraulic
- Continuous Operation: Yes
- Transmission Manufacturer: Allison
- Output Type: SAE B Pump Flange, SAE C Pump Flange, ISO 7652 Pump Flange, Driveline
- Lubricant: P = Pressure Lube, W = Wet Spline
- Intermittent Torque: 301 to 400 lb-ft, 501+ Nm
- Output Power: 51+ kW, 56+ HP
- Output Shaft Type: Smart Start – Round Shaft (1-1/4″ – 5/16″ Key), 3/4″ – 11T Pump Spline, SAE B (7/8″ – 13T) Pump Spline, SAE C (1-1/4″ – 14T) Pump Spline, DIN 5462 Pump Spline, 1410 Companion Flange, DIN 120 Flange, DIN 100 Flange
- Shaft Power: 37 HP (500 RPM), 74 HP (1000 RPM), 28 kW (500 RPM), 55 kW (1000 RPM)
- Weight: 50 lb, 22.7 kg
Key Benefits
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Ductile Iron Bearing Cap – 117% stronger than gray iron.
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Improved Seal – O-ring sealing configuration to reduce vibrational affects and improve clamp load.
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Enhanced Clutch Pack – 80% thicker steel disks in the clutch pack to resist premature tooth wear.
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Torque – Single, continuous duty torque rating.
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Clearance – Rotatable cast iron flanges to improve pump clearance.
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Positive Stop for Driveline Outputs – Eliminates oil seal damage from coupling.
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Wet Spline Lubrication Option – Provides 7 to 10 times greater shaft life.
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Speeds – Nine speed ratios including low and high-speeds.
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SmartStart – Reduces shock load at start-up for certain applications.
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Insurance – Electronic Overspeed Control (EOC) protects driven equipment.
Examples of Suitable Applications
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Fire and Rescue
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Truck Cranes
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Pumper Cleaners
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Refuse
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