The Chelsea 890 Series Power Take-Off, part number 890MAFJW-B5AF or 890MAFJWB5AF, is a hydraulic hot-shift PTO engineered specifically for Allison 3000 MD and 4000 HD Series transmissions. It mounts via a 10-bolt pattern and locates the SAE C pump output flange at the rear of the transmission, giving the pump room that a conventional side-mounted PTO cannot provide. The one-piece main shaft eliminates the input splines between the PTO body and the output extension, reducing wear points. Wet Spline Technology on the output shaft extends pump spline life under continuous-duty demand. The series carries a continuous torque rating up to 670 ft-lb and delivers up to 128 HP at 1,000 RPM. Shifting is hydraulic PowerShift. Common applications include aerial trucks, fire and rescue, refuse, and truck crane work. Call us to confirm proper fit for your specific transmission configuration.
Features
Hydraulic PowerShift (hot-shift) engagement for Allison 3000 MD and 4000 HD Series transmissions
10-bolt mounting with rear-of-transmission SAE C output flange for improved pump clearance
One-piece main shaft eliminates input splines between PTO body and output extension
Wet Spline output technology reduces pump spline wear in high-demand continuous-duty service
Continuous torque rating up to 670 ft-lb; intermittent torque rated at 501+ ft-lb
Shaft power output: 64 HP at 500 RPM, 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) Output
- Outlet Flange Type: SAE C
- Lubricant/Output: Wet Spline
- Continuous Torque: Up to 670 lb-ft (check application pages for actual torque ratings)
- Intermittent Torque: 501+ lb-ft
- 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 mounts like a standard side-mounted PTO but adds a support bracket at the rear of the transmission for stability. The clutch is positioned at the rear of the PTO housing, allowing the gear section to sit tight against the transmission for maximum clearance between the pump and surrounding chassis components. The unit is a single assembly, not a PTO paired with a separate extension. This design makes the 890 Series a practical choice for aerial trucks, fire and rescue vehicles, refuse trucks, pumper cleaners, and truck crane applications where pump space is limited and high torque output is required. The 890 Series can be specified for transmissions equipped with a cooler, retarder, both, or neither.Parts Manual: Chelsea 890 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.
