Features
10-bolt mounting for Allison and compatible automatic transmissions
Hydraulic PowerShift (hot shift) for engagement under load
Ductile iron bearing cap rated 117% stronger than gray iron
O-ring sealing configuration between housing and bearing cap improves clamp load and resists vibration
Nine speed ratios including both low and high speeds
Wet Spline Lubrication option extends shaft life 7 to 10 times over standard
SmartStart reduces shock load at engagement for applicable configurations
Electronic Overspeed Control (EOC) protects connected driven equipment
Positive Stop on driveline outputs prevents oil seal damage at the coupling
Tech Specs
- Mounting: 10-bolt aperture
- Shift Type: PowerShift (Hydraulic)
- Transmission Compatibility: Allison automatic transmissions
- Continuous Operation: Yes
- Speed Ratios: Nine, including low and high
- Bearing Cap Material: Ductile iron (117% stronger than gray iron)
- Sealing: O-ring configuration between housing and bearing cap
- Lubrication Option: Wet Spline (W) or Pressure Lube (P)
- Output Types: SAE B pump flange, SAE C pump flange, ISO 7652 pump flange, driveline
- Electronic Overspeed Control (EOC): Included
Additional Information
The Chelsea 281 Series is an evolution of the 280 Series PTO platform, introduced with structural and sealing upgrades to address vibration demands from current and future engine designs. The 80% increase in steel disc thickness within the clutch pack resists premature tooth wear during continuous-duty hydraulic engagement. Markets served by this series include fire and rescue, truck cranes, pumper cleaner, and refuse applications. Reference documents for this series 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.
