The Chelsea 890 Series Power Take-Off, part number 890UCFJW-B5AF or 890UCFJWB5AF, is a hydraulic hot-shift PTO engineered specifically for Allison 3000 MD and 4000 HD Series transmissions. The 890 Series relocates the pump mounting flange to the rear of the transmission, placing the output behind the gear section to create working clearance where a conventional side-mount PTO would crowd the frame rail. A one-piece main shaft eliminates the input splines found on PTO-plus-extension setups, and the clutch sits at the rear of the housing so the gear section tucks tightly against the transmission. Wet Spline output technology protects the PTO and pump shaft in continuous-duty operation. Continuous-duty torque rating reaches 670 ft-lb; intermittent torque is rated at 501 ft-lb or higher. Shaft power output is 64 HP at 500 RPM and 128 HP at 1,000 RPM. The unit mounts on a 10-bolt pattern and includes a rear support bracket. Common applications include aerial trucks, fire and rescue, refuse, and truck crane service. Call us to confirm proper fit for your specific Allison transmission configuration.
Features
Fits Allison 3000 MD and 4000 HD Series transmissions via FJ input gear designation
Hydraulic PowerShift (hot-shift) operation
10-bolt mounting with rear support bracket for added rigidity
SAE C (XS) output flange and shaft
Wet Spline output extends PTO and pump shaft life in demanding duty cycles
Continuous-duty torque rating up to 670 ft-lb; shaft power 64 HP at 500 RPM and 128 HP at 1,000 RPM
Tech Specs
- Transmission Application: Allison 3000 MD and 4000 HD Series
- Product Series: 890
- Mounting Type: 10-Bolt
- Shift Type: Hydraulic PowerShift (hot-shift)
- Output Shaft Type: SAE C (XS)
- Outlet Flange Type: SAE C
- Lubricant/Output: Wet Spline
- Continuous Torque: 670 ft-lb (verify actual rating on Chelsea application pages)
- Intermittent Torque: 501+ ft-lb
- 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
The Chelsea 890 Series is a single-unit design, not a PTO paired with a bolt-on extension. The one-piece main shaft eliminates the intermediate spline connection between the gear section and the output, reducing potential wear points. The clutch assembly is positioned at the rear of the housing, allowing the gear section to seat close to the transmission case for tighter overall packaging. A secondary mounting bracket at the rear of the transmission provides additional support beyond a standard side-mount PTO installation. The 890 Series can be configured for Allison transmissions equipped with a cooler, a retarder, both, or neither. Typical service environments include aerial work platforms, fire and rescue pumpers, refuse collection trucks, and truck-mounted cranes, where both pump clearance and sustained high-torque output are priorities. Part number 890UCFJW-B5AF is also referenced as SP890UCFJW-B5AF. Contact Pro Gear and Transmission to confirm the correct configuration for your vehicle and transmission build.Parts Manual: Chelsea 890 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.
