The Chelsea 281GDFJP-H3AC is a 281 Series PowerShift Power Take-Off built for 10-bolt automatic transmissions, including Allison applications. The 281 Series uses hydraulic shifting for hot-shift, continuous-duty operation and mounts directly to the 10-bolt aperture common on Allison and Caterpillar transmissions. Output options across the 281 Series include SAE B and SAE C pump flanges, ISO 7652 pump flange, and driveline configurations. The series carries a continuous torque rating of 390 lb-ft and delivers up to 74 HP at 1,000 RPM. Key upgrades over the predecessor 280 Series include a ductile iron bearing cap rated 117% stronger than gray iron, an o-ring housing-to-bearing-cap seal, and clutch pack steel discs increased 80% in thickness. Part number 281GDFJP-H3AC or SP281GDFJP-H3AC. Available from Pro Gear and Transmission.
Features
10-bolt mounting for Allison and Caterpillar automatic transmissions
Hydraulic PowerShift (hot shift) for continuous-duty operation
Continuous torque rating of 390 lb-ft (529 Nm) at series level
Ductile iron bearing cap, 117% stronger than gray iron predecessor
Clutch pack steel discs increased 80% in thickness over 280 Series
O-ring sealing between housing and bearing cap for improved clamp load
Tech Specs
- Mounting Type: 10-Bolt
- Shift Type: PowerShift (Hydraulic)
- Continuous Operation: Yes
- Series Continuous Torque: 390 lb-ft (529 Nm)
- Series Intermittent Torque: 301-400 lb-ft
- Series Output Power: 56+ HP (51+ kW)
- Series Shaft Power: 37 HP at 500 RPM / 74 HP at 1,000 RPM
- Compatible Transmission Manufacturer: Allison
- Output Types (series): SAE B Pump Flange, SAE C Pump Flange, ISO 7652 Pump Flange, Driveline
- Lubrication: Pressure Lube / Wet Spline options
Additional Information
The 281 Series is an evolution of the Chelsea 280 Series PTO. Improvements target the damaging vibrational effects of modern engine designs. The ductile iron bearing cap replaces the gray iron cap of the 280 Series and is rated 117% stronger. An o-ring sealing configuration between the housing and bearing cap replaces the previous gasket-style seal, improving clamp load. Steel discs within the clutch pack are 80% thicker to resist premature tooth wear. The series also supports nine speed ratios, an optional wet spline lubrication system for extended shaft life (7-10 times greater than standard), SmartStart for reduced shock load at engagement, and Electronic Overspeed Control (EOC) for driven equipment protection. Typical market applications include fire and rescue apparatus, truck cranes, pumper-cleaner units, and refuse vehicles. Reference documents: 281/288 Series Parts List HY25-2281-M1/US; 267/281/288/871/878 Series Owner's Manual; Chelsea PTO Stud Kits HY25-2002-M1_US.Parts Manual: Chelsea 281 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.
