281GMFJR-B3RF Chelsea PTO Assembly

The Chelsea 281 Series Power Take-Off, part number 281GMFJR-B3RF or 281GMFJRB3RF, is a hydraulically shifted hot-shift PTO designed for automatic transmissions with a 10-bolt aperture, including Allison and Caterpillar transmissions. The 281 Series is the evolved successor to the top-selling Chelsea 280 Series, with a ductile iron bearing cap rated 117% stronger than gray iron and an 80% thicker clutch pack to resist premature tooth wear. An O-ring sealing configuration between the housing and bearing cap improves clamp load and reduces vibration-related wear. Nine speed ratios cover both low and high-speed applications. Rotatable cast iron flanges reduce pump clearance interference. The wet spline lubrication option extends shaft life by 7 to 10 times. Call us to confirm proper fit for your application.

Features

10-bolt aperture mount, compatible with Allison and Caterpillar automatic transmissions
Hydraulic PowerShift (hot-shift) operation for engagement under load
Ductile iron bearing cap, 117% stronger than gray iron predecessor
80% thicker steel discs in the clutch pack to resist premature tooth wear
O-ring sealing configuration between housing and bearing cap improves clamp load and reduces vibration damage
Nine speed ratios including low and high speeds; wet spline lubrication option extends shaft life 7 to 10 times
Electronic Overspeed Control (EOC) protects driven equipment; SmartStart reduces shock load at engagement
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 Manufacturers: Allison, Caterpillar (10-bolt aperture automatics)
• Continuous Operation: Yes
• Single continuous duty torque rating (see application pages for actual torque values)
• Nine speed ratios including low and high speeds
• Output Types: 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
• Wet spline option provides 7 to 10 times greater shaft life
• Electronic Overspeed Control (EOC): included
• SmartStart shock-load reduction: available for select applications

Additional Information

The Chelsea 281 Series is suited for demanding mobile hydraulic applications including fire and rescue apparatus, truck cranes, pumper-cleaner units, and refuse vehicles. The 281 Series replaces and improves upon the Chelsea 280 Series with a stronger bearing cap, enhanced clutch pack, and improved sealing. Reference documents available from Parker Chelsea 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.