Features
Hydraulic PowerShift (hot-shift) operation for Allison automatic transmissions with 10-bolt aperture
Ductile iron bearing cap - 117% stronger than gray iron predecessor
O-ring sealing configuration between housing and bearing cap reduces vibrational effects and improves clamp load
Enhanced clutch pack with 80% thicker steel discs to resist premature tooth wear
Nine speed ratios including dedicated low and high speeds
Wet spline lubrication option provides 7 to 10 times greater shaft life
SmartStart feature reduces shock load at start-up; Electronic Overspeed Control (EOC) protects driven equipment
Rotatable cast-iron flanges reduce pump clearance interference; positive stop for driveline outputs eliminates oil seal damage
Tech Specs
- Mounting Type: 10-Bolt
- Shift Type: Hydraulic PowerShift (Hot-Shift)
- Compatible Transmission Manufacturer: Allison
- Continuous Torque Rating: 390 lb-ft (529 Nm) - see application pages for actual torque rating
- Intermittent Torque Range: 301 to 400 lb-ft (501+ Nm)
- 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)
- Output Types Available: SAE B pump flange, SAE C pump flange, ISO 7652 pump flange, driveline
- Output Shaft Options: SmartStart round shaft (1-1/4 in. with 5/16 in. key), 3/4 in. 11-tooth pump spline, SAE B 7/8 in. 13-tooth pump spline, SAE C 1-1/4 in. 14-tooth pump spline, DIN 5462 pump spline, 1410 companion flange, DIN 120 flange, DIN 100 flange
- Lubricant Options: Pressure lube (P), Wet Spline (W)
- Speed Ratios: Nine ratios including low and high speeds
- Series: Chelsea 281
Additional Information
Parts manual and diagrams: Chelsea 281 Series PTO parts list with prices
Matched by full model number. Check the mounting, input gear and output against the unit you are replacing before you order. Look up any Chelsea, Muncie or Bezares number on our Muncie to Chelsea PTO cross reference.

