The Chelsea 899 Series Power Take-Off, part number 899HFFJW-M5XY or 899HFFJWM5XY, is a constant-mesh PTO engineered specifically for Allison 4700 Series transmissions. Mounting via a 10-bolt pattern, it positions the pump output flange to the rear of the transmission, tucking the gear section tightly against the housing for improved clearance between the pump and the frame rail. An additional bracket at the rear of the transmission provides extra support. The SAE C output shaft uses a 1-1/4 in., 14-tooth wet-spline interface, which extends pump spline life in demanding duty cycles. Continuous torque capacity reaches up to 670 ft-lb (verify against application pages for your specific configuration). Common applications include aerial trucks, fire and rescue apparatus, truck cranes, and refuse trucks. Call us to confirm proper fit for your chassis and transmission build.
Features
Fits Allison 4700 Series transmissions, 10-bolt mounting
Constant-mesh (non-shiftable) operation
SAE C outlet flange with 1-1/4 in., 14-tooth wet-spline output shaft
Continuous torque up to 670 ft-lb; intermittent torque rated 501+ lb-ft
Output power 56+ HP (51+ kW); shaft power 64 HP at 500 RPM, 128 HP at 1,000 RPM
Rear-mounted pump flange relocates output behind the transmission for improved pump and frame clearance
Tech Specs
- Transmission Manufacturer: Allison 4700 Series
- Mounting Type: 10-Bolt
- Shift Type: Constant Mesh
- Outlet Flange Type: SAE C
- Output Shaft Type: SAE C, 1-1/4 in. - 14-Tooth Wet-Spline Pump Spline
- Intermittent Torque: 501+ lb-ft (501+ Nm)
- Continuous Torque: Up to 670 lb-ft (908 Nm) - check application pages for actual torque ratings
- Output Power: 56+ HP (51+ kW)
- Shaft Power: 64 HP (48 kW) at 500 RPM; 128 HP (95 kW) at 1,000 RPM
Additional Information
Parts Manual: Chelsea 899 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.
