The Chelsea 281GMFJP-N5AC is a 281 Series hydraulic PowerShift power take-off designed for automatic transmissions with a 10-bolt aperture, including Allison transmissions. The 281 Series mounts directly to the 10-bolt PTO pad and supports continuous operation duty cycles. Key structural improvements over the predecessor 280 Series include a ductile iron bearing cap rated 117% stronger than gray iron, an o-ring sealing configuration between the housing and bearing cap for improved clamp load, and clutch pack steel discs that are 80% thicker to resist premature tooth wear. The series carries a continuous torque rating of 390 lb-ft and supports output options including SAE B and SAE C pump flanges as well as driveline output. Common markets include fire and rescue, refuse, truck cranes, and pumper-cleaner applications. Available from Pro Gear and Transmission.
Features
281 Series hydraulic PowerShift (hot shift) PTO
10-bolt mounting for Allison and compatible automatic transmissions
Continuous duty operation rated at 390 lb-ft torque
Ductile iron bearing cap, 117% stronger than gray iron predecessor
Clutch pack steel discs increased 80% in thickness over prior 280 Series
O-ring sealing between housing and bearing cap for improved clamp load
Tech Specs
- Mounting Type: 10-Bolt
- Shift Type: PowerShift (Hydraulic)
- Transmission Compatibility: Allison automatic transmissions (10-bolt aperture)
- Continuous Torque: 390 lb-ft (529 Nm)
- Continuous Operation: Yes
- Output Types: SAE B Pump Flange, SAE C Pump Flange, ISO 7652 Pump Flange, Driveline
- Output Shaft Options: 3/4" 11-tooth pump spline, SAE B 7/8" 13-tooth pump spline, SAE C 1-1/4" 14-tooth pump spline, 1-1/4" round shaft with 5/16" key, 1410 companion flange
- Shaft Power: 37 HP at 500 RPM, 74 HP at 1000 RPM
Additional Information
The 281 Series is an evolution of the Chelsea 280 Series PTO, with targeted structural upgrades to address vibrational effects from modern engine designs. The ductile iron bearing cap replaces the gray iron cap of the 280 Series and provides a 117% strength increase. The wet spline lubrication option (where specified) is designed to provide 7 to 10 times greater shaft life compared to dry spline configurations. Electronic Overspeed Control (EOC) is available to protect driven equipment. Nine speed ratios are offered across the 281 Series, spanning low- and high-speed configurations. Rotatable cast iron flanges allow adjustment for pump clearance at installation. Applicable Parker Chelsea reference documents include the 281/288 Series Parts List (HY25-2281-M1/US) and the 267/281/288/871/878 Series Owner's Manual.Parts Manual: Chelsea 281 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.
