The Chelsea 281GMKVP-B5RS is a 281 Series Power Take-Off built for automatic transmissions with a 10-bolt aperture, including Allison and Caterpillar applications. It uses hydraulic PowerShift engagement, making it a hot-shift unit suited for continuous-duty operation. The 281 Series carries a continuous torque rating of 390 lb-ft at the series level and delivers output power of 56 HP or more. Nine speed ratios are available across the series, covering both low- and high-speed applications. The ductile iron bearing cap is 117% stronger than the gray iron used in the predecessor 280 Series, and an o-ring sealing configuration between the housing and bearing cap improves clamp load. Steel discs in the clutch pack have been increased 80% in thickness to resist premature wear. Available from Pro Gear and Transmission.
Features
Hydraulic PowerShift (hot-shift) engagement for automatic transmissions
10-bolt mounting aperture, compatible with Allison and Caterpillar transmissions
Ductile iron bearing cap, 117% stronger than the gray iron used in the 280 Series
O-ring sealing between housing and bearing cap for improved clamp load
80% thicker steel discs in the clutch pack to reduce premature tooth wear
Continuous-duty rated; nine speed ratios available across the 281 Series
Tech Specs
- Mounting Type: 10-Bolt
- Shift Type: PowerShift (Hydraulic)
- Continuous Operation: Yes
- Transmission Manufacturer: Allison
- Continuous Torque (Series): 390 lb-ft / 529 Nm
- Output Power (Series): 56+ HP / 51+ kW
- Shaft Power: 37 HP at 500 RPM, 74 HP at 1000 RPM
- Output Types Available: SAE B Pump Flange, SAE C Pump Flange, ISO 7652 Pump Flange, Driveline
- Output Shaft Types Available: 1-1/4" Round (5/16" Key), 3/4"-11T Pump Spline, SAE B 7/8"-13T, SAE C 1-1/4"-14T, DIN 5462, 1410 Companion Flange, DIN 120 Flange, DIN 100 Flange
- Lubrication: Pressure Lube / Wet Spline option
- Speed Ratios: Nine ratios (low and high speeds)
Additional Information
The 281 Series is an evolution of the Chelsea 280 Series PTO, introduced to address vibrational effects from modern engine designs. Common markets include fire and rescue, truck cranes, pumper-cleaner, and refuse vehicles. The Electronic Overspeed Control (EOC) option protects driven equipment. The SmartStart feature is available on select configurations to reduce shock load at start-up. Wet spline lubrication provides 7 to 10 times greater shaft life compared to standard lubrication. Rotatable cast iron flanges allow pump clearance adjustment. Relevant Parker Chelsea documents 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.
