Description
The Chelsea 281GMFJP-B5XR or 281GMFJPB5XR is a 281 Series hydraulically shifted (PowerShift) Power Take-Off designed for automatic transmissions with a 10-bolt aperture, including Allison and Caterpillar transmissions. It carries a single, continuous duty torque rating and delivers output power at 51+ kW (56+ HP). The 281 Series is an evolution of the 280 Series platform, introducing a ductile iron bearing cap rated 117% stronger than gray iron, an O-ring sealing configuration between the housing and bearing cap, and an 80% increase in steel disc thickness within the clutch pack. Nine speed ratios cover both low and high ranges. The cross-reference for this part is 280GMFJP-B5XR or 280GMFJPB5XR. Call us to confirm proper fit for your application.
Features
Hydraulic PowerShift (hot-shift) operation for 10-bolt automatic transmission apertures, including Allison and Caterpillar
Ductile iron bearing cap rated 117% stronger than gray iron for increased durability
O-ring sealing configuration between housing and bearing cap improves clamp load and resists vibrational effects
80% thicker steel discs in the clutch pack resist premature tooth wear
Nine speed ratios available, spanning low and high speeds
Wet Spline Lubrication option extends shaft service life 7 to 10 times compared to standard lubrication
SmartStart feature reduces shock load at start-up; Electronic Overspeed Control (EOC) protects driven equipment
Rotatable cast-iron flanges reduce interference and improve pump clearance; Positive Stop for driveline outputs eliminates oil seal damage from coupling
Cross-references: 280GMFJP-B5XR or 280GMFJPB5XR
Tech Specs
- Mounting Type: 10-Bolt
- Shift Type: PowerShift (Hydraulic / Hot-Shift)
- Continuous Operation: Yes
- Continuous Torque: 390 lb-ft (529 Nm), verify actual rating on application pages
- Output Power: 56+ HP (51+ kW)
- Shaft Power: 37 HP at 500 RPM / 74 HP at 1000 RPM (28 kW at 500 RPM / 55 kW at 1000 RPM)
- Transmission Compatibility: Allison and Caterpillar automatic transmissions (10-bolt aperture)
- Output Types: SAE B Pump Flange, SAE C Pump Flange, ISO 7652 Pump Flange, Driveline
- Output Shaft Options: SmartStart Round Shaft (1-1/4″ – 5/16″ Key), 3/4″-11T Pump Spline, SAE B (7/8″-13T), SAE C (1-1/4″-14T), DIN 5462, 1410 Companion Flange, DIN 120 Flange, DIN 100 Flange
- Lubricant Options: Pressure Lube (P) / Wet Spline (W)
- Speed Ratios: Nine (low and high speeds included)
- Cross Reference: 280GMFJP-B5XR or 280GMFJPB5XR
- Typical Markets: Fire and Rescue, Truck Cranes, Pumper Cleaner, Refuse
Additional Information
Parts Manual: Chelsea 281 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.









