The Chelsea 890 Series Power Take-Off part number 890UDFJW-B5AF or 890UDFJWB5AF is a hydraulic PowerShift PTO engineered specifically for Allison 3000 MD and 4000 HD Series transmissions. It mounts via a 10-bolt pattern and delivers an SAE C output shaft with wet-spline lubrication, protecting pump spline interfaces in demanding duty cycles. Continuous-duty torque rating reaches 670 ft-lb; intermittent torque is rated at 501+ ft-lb. Shaft power output is 64 HP at 500 RPM and 128 HP at 1,000 RPM. The single one-piece main shaft eliminates input splines between the PTO body and the output extension, while the clutch positioned at the rear of the housing tucks the gear section tightly against the transmission for improved frame-rail clearance. Common applications include aerial trucks, fire and rescue apparatus, truck cranes, and refuse trucks. Call us to confirm proper fit for your specific Allison transmission configuration.
Features
Fits Allison 3000 MD and 4000 HD Series transmissions via 10-bolt mounting
Hydraulic PowerShift (hot shift) engagement
SAE C output shaft with wet-spline technology for extended pump spline life
Continuous-duty torque rating up to 670 ft-lb; intermittent torque 501+ ft-lb
Shaft power: 64 HP at 500 RPM, 128 HP at 1,000 RPM
One-piece main shaft design with rear-positioned clutch for improved pump clearance
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) with Wet-Spline
- Outlet Flange Type: SAE C
- Continuous Torque Rating: 670 ft-lb (check application pages for actual torque ratings)
- Intermittent Torque: 501+ ft-lb
- Shaft Power: 64 HP at 500 RPM; 128 HP at 1,000 RPM
- Output Power: 56+ HP
Additional Information
The Chelsea 890 Series was designed to address tight pump clearance on Allison 3000 and 4000 Series applications. Unlike a standard side-mounted PTO paired with a separate extension, the 890 is a single unit with a one-piece main shaft, eliminating the input splines that typically sit between the PTO body and an output extension. The clutch is positioned at the rear of the housing so the gear section nests tightly against the transmission, relocating the pump mounting flange rearward and providing additional space between the pump and the frame rail. An additional support bracket at the rear of the transmission supplements the standard side-mount attachment points. Wet-Spline Technology is standard across the 890 Series, reducing friction and wear on the output and pump shaft splines under continuous or high-cycle duty. Typical applications include aerial work trucks, fire and rescue pumpers, refuse trucks, truck cranes, and snow and ice equipment. The unit can be ordered for transmissions equipped with or without a cooler, a retarder, or both.Parts Manual: Chelsea 890 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.
