The Chelsea 899HBFJW-M5XS or 899HBFJWM5XS is a constant-mesh power take-off assembly built specifically for Allison 4700 Series transmissions. It mounts via a 10-bolt pattern and uses an SAE C ("XS") extended output shaft that relocates the pump mounting flange to the rear of the transmission, tucking the housing tightly against the transmission for improved pump clearance between the unit and the frame rail. The output spline incorporates Wet Spline technology to extend PTO and pump shaft life under demanding duty cycles. Continuous-duty torque capacity reaches 670 ft-lb (verify against application pages for your specific configuration), with intermittent torque rated at 501+ lb-ft. Shaft power output at 1,000 RPM is rated at 128 HP. Typical applications include aerial trucks, fire and rescue apparatus, refuse trucks, and truck cranes. Call us to confirm proper fit for your specific Allison 4700 configuration.
The Chelsea 899 Series is engineered for aerial trucks, fire and rescue vehicles, refuse trucks, and truck cranes where pump space is limited and high continuous torque is required. The one-piece main shaft eliminates input splines between the PTO body and the output extension, and the unit mounts like a standard side-mounted PTO with an additional rear bracket for support. The 899 Series can be ordered for transmissions equipped with or without a cooler or retarder.
Features
Fits Allison 4700 Series transmissions, 10-bolt mounting
Constant-mesh (non-shiftable) shift type
SAE C ("XS") extended output shaft relocates pump flange to rear of transmission for improved clearance
Wet Spline output extends PTO and pump shaft service life
Continuous-duty torque up to 670 ft-lb; intermittent torque 501+ lb-ft (verify on application pages)
Shaft power: 64 HP at 500 RPM, 128 HP at 1,000 RPM
Tech Specs
- Transmission Fitment: Allison 4700 Series
- Mounting Type: 10-Bolt
- Shift Type: Constant Mesh
- Output Shaft Type: SAE C ("XS") Extended Wet-Spline Output - 1-1/4" - 14T Pump Spline
- Outlet Flange Type: SAE C
- Intermittent Torque: 501+ lb-ft (501+ Nm)
- Continuous Torque: Up to 670 lb-ft / 908 Nm (check application pages for actual rating)
- Output Power: 56+ HP (51+ kW)
- Shaft Power at 500 RPM: 64 HP (48 kW)
- Shaft Power at 1,000 RPM: 128 HP (95 kW)
- Lubricant Option: Wet Spline (W)
Additional Information
The Chelsea 899 Series is engineered for aerial trucks, fire and rescue vehicles, refuse trucks, and truck cranes where pump space is limited and high continuous torque is required. The one-piece main shaft eliminates input splines between the PTO body and the output extension, and the unit mounts like a standard side-mounted PTO with an additional rear bracket for support. The 899 Series can be ordered for transmissions equipped with or without a cooler or retarder.
