The Chelsea 890RAFJW-B5AF or 890RAFJWB5AF is a hydraulic PowerShift PTO assembly from the 890 Series, engineered specifically for Allison 3000 MD and 4000 HD Series transmissions. It mounts via a 10-bolt pattern and positions the SAE C output flange at the rear of the transmission, moving the pump mounting point back to open clearance between the pump and the frame rail. The main shaft is a single one-piece design, eliminating the input splines between the PTO body and the output extension. A wet-spline output extends pump shaft life under continuous-duty loads. The clutch sits at the rear of the PTO housing so the gear section tucks tightly against the transmission. Continuous-duty torque reaches 670 ft-lb; intermittent torque is rated at 501+ ft-lb. Shaft output power runs 64 HP at 500 RPM and 128 HP at 1,000 RPM. Common applications include aerial trucks, fire and rescue, refuse vehicles, and truck cranes. A genuine Chelsea part from Pro Gear and Transmission. Call us to confirm proper fit for your specific Allison transmission configuration.
The Chelsea 890 Series fits between the transmission and the frame rail, locating the pump output to the rear of the Allison transmission for improved clearance. It mounts like a standard side-mounted PTO but includes an additional support bracket at the rear of the transmission. The 890 Series is a single-unit assembly, not a PTO paired with a separate extension. The clutch is positioned at the rear of the housing so the gear section tucks tightly against the transmission case. The wet-spline output is standard across the 890 Series to protect pump shaft splines in demanding duty cycles. Typical applications include aerial trucks, fire and rescue pumpers, refuse trucks, truck cranes, and snow and ice equipment.
Features
890 Series hydraulic PowerShift (hot shift) engagement
10-bolt mounting for Allison 3000 MD and 4000 HD Series transmissions
SAE C ("XS") output shaft with wet-spline technology for extended pump shaft life
One-piece main shaft eliminates input splines between PTO body and output extension
Continuous-duty torque rating: 670 ft-lb; intermittent torque: 501+ ft-lb
Shaft 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
- Output Shaft Type: SAE C ("XS") Output
- Outlet Flange Type: SAE C
- Lubricant/Spline: Wet Spline
- Continuous Torque: 670 ft-lb (check application pages for actual torque ratings)
- 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 fits between the transmission and the frame rail, locating the pump output to the rear of the Allison transmission for improved clearance. It mounts like a standard side-mounted PTO but includes an additional support bracket at the rear of the transmission. The 890 Series is a single-unit assembly, not a PTO paired with a separate extension. The clutch is positioned at the rear of the housing so the gear section tucks tightly against the transmission case. The wet-spline output is standard across the 890 Series to protect pump shaft splines in demanding duty cycles. Typical applications include aerial trucks, fire and rescue pumpers, refuse trucks, truck cranes, and snow and ice equipment.
Parts Manual: Chelsea 890 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.
