281GDFJP-S8RK Chelsea PTO Assembly

The Chelsea 281 Series Power Take-Off, part number 281GDFJP-S8RK or 281GDFJPS8RK, is a hydraulically shifted hot shift PTO designed for 10-bolt automatic transmission apertures, commonly found on Allison transmissions. The 281 Series is an evolution of the Chelsea 280 Series, incorporating a ductile iron bearing cap rated 117% stronger than gray iron, an 80% thicker clutch pack steel disc thickness over the predecessor, and an O-ring sealing configuration that improves clamp load and reduces vibration effects. The series carries a continuous torque rating of 390 lb-ft and offers nine speed ratios covering both low and high speed ranges. Output options include SAE B and SAE C pump flanges, ISO and DIN flange configurations, and driveline outputs with a positive-stop feature that eliminates oil seal damage at the coupling. A wet spline lubrication option extends shaft life 7 to 10 times compared to standard lubrication. Electronic Overspeed Control (EOC) protects driven equipment, and SmartStart reduces shock load at start-up on applicable configurations. Call us to confirm proper fit for your transmission and application.

Features

10-bolt hydraulic PowerShift (hot shift) design for Allison automatic transmissions
Ductile iron bearing cap - 117% stronger than gray iron predecessor
Enhanced clutch pack with 80% thicker steel discs to resist premature tooth wear
O-ring sealing configuration between housing and bearing cap for improved clamp load and vibration resistance
Nine speed ratios available, including low and high speed ranges
Wet spline lubrication option provides 7 to 10 times greater shaft life
Electronic Overspeed Control (EOC) protects driven equipment; SmartStart reduces start-up shock load
Positive-stop driveline output eliminates oil seal damage from coupling

Tech Specs

• Mounting Type: 10-Bolt
• Shift Type: Hydraulic (PowerShift / Hot Shift)
• Transmission Compatibility: Allison automatic transmissions (10-bolt aperture)
• Continuous Torque Rating: 390 lb-ft (529 Nm) - verify actual rating on application pages
• Output Types: SAE B Pump Flange, SAE C Pump Flange, ISO 7652 Pump Flange, DIN 100 Flange, DIN 120 Flange, 1410 Companion 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
• Speed Ratios: Nine ratios available, including low and high speed
• Lubrication: Pressure Lube (P) or Wet Spline (W) option
• Continuous Operation: Yes
• Series: Chelsea 281 Series (evolution of 280 Series)

Additional Information

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