Chelsea 899 Series PTO

The Chelsea 899 Series PTO is a constant mesh, non-shiftable power take-off designed specifically for Allison 4700 transmissions. It delivers exceptional clearance and the highest torque rating in its class—up to 670 lb-ft, making it ideal for heavy-duty vocational applications.

The 899 Series PTO mounts neatly between the transmission and the truck’s frame rail, with the pump output positioned at the rear of the transmission for ample space and accessibility. It installs like a standard side-mounted PTO but includes an additional rear support bracket for improved strength and stability.

Engineered as a single integrated unit, not a multi-piece assembly, the Chelsea 899 Series PTO features a one-piece main shaft that eliminates the need for input splines between the PTO and output extension. The rear-mounted pump interface allows the gear housing to fit tightly against the transmission, maximizing under-truck clearance.

The output utilizes Wet Spline Technology, significantly extending PTO and pump shaft life in demanding, high-torque conditions.

Available for transmissions with or without a cooler or retarder, the Chelsea 899 Series PTO is an ideal solution for aerial trucks, fire and rescue vehicles, snow and ice equipment, and other applications where space, torque capacity, and durability are critical.

Technical Specifications

• Intermittent Torque: 501+ lb-ft, 501+ Nm
• Mounting Type: 10-Bolt
• Outlet Flange Type: SAE C
• Output Power: 56+ HP, 51+ kW
• Output Shaft Type: SAE C (1-1/4″ – 14T) Pump Spline
• Shift Type: Constant Mesh
• Continuous Torque: De-Rate Torque Rating 30% (Check Application Pages for Actual Torque Ratings)
• Weight: 86 lb, 39 kg
• Lubricant: W = Wet Spline

Key Benefits

• Extended shaft to improve pump clearance

• Continuous-Duty Torque Rating up to 670 ft-lbs

• Wet-Spline Option to extend PTO/Pump shaft life

• Two-Year Warranty

Examples of Suitable Applications

• Fire & Rescue Trucks

• Pumper Cleaner

• Truck Cranes

• Refuse Trucks