281GMFJW-B3RY Chelsea PTO Assembly

The Chelsea 281 Series Power Take-Off, part number 281GMFJW-B3RY or 281GMFJWB3RY, is a hydraulically shifted hot-shift PTO engineered for automatic transmissions with a 10-bolt aperture, including Allison and Caterpillar transmissions. It mounts with a 10-bolt pattern and delivers nine speed ratios covering both low and high ranges. The 281 Series is an evolution of the 280 Series, featuring a ductile iron bearing cap rated 117% stronger than gray iron, an o-ring sealing configuration between housing and bearing cap for improved clamp load, and an 80% thicker steel clutch pack to resist premature tooth wear. A Wet Spline Lubrication option extends shaft life by 7 to 10 times. Rotatable cast-iron flanges reduce interference issues, and the Positive Stop feature on driveline outputs eliminates oil seal damage from coupling. Electronic Overspeed Control (EOC) protects driven equipment, and the optional SmartStart feature reduces shock load at start-up. Typical markets include fire and rescue, truck cranes, pumper cleaner, and refuse applications. Call us to confirm proper fit for your application.

Features

Hydraulic PowerShift (hot-shift) operation for use with 10-bolt automatic transmissions, including Allison and Caterpillar
Ductile iron bearing cap is 117% stronger than gray iron predecessor
O-ring sealing configuration between housing and bearing cap improves clamp load and reduces vibrational effects
Enhanced clutch pack with 80% thicker steel discs to resist premature tooth wear
Nine speed ratios including low and high speeds
Wet Spline Lubrication option provides 7 to 10 times greater shaft life
Electronic Overspeed Control (EOC) protects driven equipment; SmartStart reduces shock load at start-up
Rotatable cast-iron flanges reduce pump clearance interference; Positive Stop eliminates oil seal damage on driveline outputs

Tech Specs

• Mounting Type: 10-Bolt aperture (fits Allison and Caterpillar automatic transmissions)
• Shift Type: Hydraulic PowerShift (hot-shift)
• Continuous Operation: Yes
• Speed Ratios: Nine, including low and high speeds
• Continuous Torque (series rating): 390 lb-ft (529 Nm) - verify actual rating on application pages
• Intermittent Torque (series range): 301 to 400 lb-ft (501+ Nm)
• Output Power: 56+ HP (51+ kW)
• Shaft Power: 37 HP at 500 RPM / 74 HP at 1,000 RPM (28 kW at 500 RPM / 55 kW at 1,000 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. 11T Pump Spline, SAE B 7/8 in. 13T Pump Spline, SAE C 1-1/4 in. 14T Pump Spline, DIN 5462 Pump Spline, 1410 Companion Flange, DIN 120 Flange, DIN 100 Flange
• Lubrication: Pressure Lube or Wet Spline options
• NMFC Code: 125820 - Hydraulic PTOs, Pumps, Motors, etc.

Additional Information

Parts Manual: Chelsea 281 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.