Features
Ductile iron bearing cap, 117% stronger than gray iron for improved durability
O-ring sealing configuration between housing and bearing cap to reduce vibration effects and improve clamp load
CLutch pack steel disks are 80% thicker to resist premature tooth wear
Nine speed ratios including low and high speeds
Electronic Overspeed Control (EOC) protects driven equipment from overspeed damage
Wet Spline Lubrication option provides 7 to 10 times greater shaft life
SmartStart feature reduces shock load at start-up for select applications
Rotatable cast iron flanges reduce interference and improve pump clearance
Positive Stop for driveline outputs eliminates oil seal damage from coupling
Hose included with assembly
Tech Specs
- Mounting Type: 10-Bolt
- Shift Type: PowerShift (Hydraulic) - Hot Shift
- Transmission Compatibility: Allison automatic transmissions (10-bolt aperture)
- Continuous Operation: Yes
- Output Types: SAE B Pump Flange, SAE C Pump Flange, ISO 7652 Pump Flange, Driveline
- Output Shaft Options: 3/4 in. - 11T Pump Spline, SAE B 7/8 in. - 13T Pump Spline, SAE C 1-1/4 in. - 14T Pump Spline, SmartStart Round Shaft 1-1/4 in. - 5/16 in. Key, 1410 Companion Flange
- Series Continuous Torque Rating: 390 lb-ft (529 Nm) - see application pages for actual torque ratings
- Series Shaft Power: 37 HP at 500 RPM, 74 HP at 1000 RPM
- Speed Ratios Available: Nine (low and high included)
- Lubrication Options: Pressure Lube, Wet Spline
- Markets: Fire and Rescue, Truck Cranes, Pumper Cleaner, Refuse
Additional Information

The Chelsea 281 Series is covered by the 281/288 Series Parts List (document HY25-2281-M1/US) and the 267/281/288/871/878 Series Owner's Manual. These documents detail component identification and service procedures for the 281 Series PTO family.
Parts manual and diagrams: Chelsea 281 Series PTO parts list with prices
