Description
The Chelsea 281 Series Power Take-Off Assembly, part number 281GMFJP-G5SD or 281GMFJPG5SD, is a hydraulically shifted hot-shift PTO engineered for automatic transmissions with a 10-bolt aperture, commonly fitted to Allison and Caterpillar transmissions. The 281 Series is an evolution of the 280 Series, featuring a ductile iron bearing cap rated 117% stronger than gray iron and an 80% thicker clutch pack steel disc for improved resistance to premature tooth wear. An o-ring sealing configuration between the housing and bearing cap reduces vibrational effects and improves clamp load. Nine speed ratios cover both low and high ranges, and the series is rated for continuous operation. Electronic Overspeed Control (EOC) and an optional SmartStart shaft protect driven equipment and reduce startup shock loads. A genuine Chelsea part, sold by Pro Gear and Transmission. Call us to confirm proper fit for your specific transmission and application.
Features
10-bolt mounting aperture for Allison and Caterpillar automatic transmissions
Hydraulic PowerShift (hot-shift) operation supports continuous-duty use
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 reduces vibration effects and improves clamp load
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 option reduces shock load at startup
Tech Specs
- Mounting Type: 10-Bolt
- Shift Type: Hydraulic PowerShift (hot-shift)
- Continuous Operation: Yes
- Continuous Torque Rating: 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
- Output Types: SAE B Pump Flange, SAE C Pump Flange, ISO 7652 Pump Flange, Driveline
- Output Shaft Options: 1-1/4″ round with 5/16″ key (SmartStart), 3/4″-11T pump spline, SAE B 7/8″-13T pump spline, SAE C 1-1/4″-14T pump spline, DIN 5462 pump spline, 1410 companion flange, DIN 120 flange, DIN 100 flange
- Lubrication: Pressure Lube (P) or Wet Spline (W) option
- Speed Ratios: Nine (low and high range included)
- Market Applications: 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.
