The Chelsea 890 Series Power Take-Off, part number 890XFFJW-B5XK or 890XFFJWB5XK, 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 uses an SAE C ("XS") output flange. Hydraulic PowerShift engagement means the unit can be shifted under load without interrupting hydraulic flow. The one-piece main shaft eliminates the input splines found on PTO-plus-extension setups, and the clutch is positioned at the rear of the housing so the gear section sits tight against the transmission for tighter frame-rail clearance. Wet-spline output technology reduces wear on the pump shaft during demanding duty cycles. The 890 Series continuous-duty torque rating reaches 670 ft-lb, with intermittent capacity exceeding 501 ft-lb. Shaft power output is 64 HP at 500 RPM and 128 HP at 1,000 RPM. Common applications include aerial trucks, fire and rescue vehicles, refuse trucks, and truck cranes. Call us to confirm proper fit for your specific transmission configuration.
Features
Fits Allison 3000 MD and 4000 HD Series transmissions via 10-bolt mounting
Hydraulic PowerShift engagement for on-the-go activation under load
Continuous-duty torque rating up to 670 ft-lb; intermittent torque exceeds 501 ft-lb
SAE C ("XS") output shaft with wet-spline technology to extend pump shaft service life
One-piece main shaft design eliminates input splines between PTO body and output extension
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
- Outlet Flange Type: SAE C
- Output Shaft Type: SAE C ("XS") Output
- Lubricant: Wet Spline
- Continuous Torque: 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 (500 RPM), 128 HP (1,000 RPM) / 48 kW (500 RPM), 95 kW (1,000 RPM)
Additional Information
The Chelsea 890 Series is designed to mount like a standard side-mounted PTO while adding a support bracket at the rear of the transmission for added stability. Unlike a PTO-and-extension combination, the 890 is a single unit with a one-piece shaft, which removes the intermediate spline connection and the wear point it creates. The clutch assembly sits at the rear of the housing, allowing the gear section to tuck closely against the transmission body and maximize clearance between the pump mounting flange and the frame rail. This geometry makes the 890 Series a practical choice for aerial trucks, fire and rescue units, refuse vehicles, and truck cranes where pump space is constrained and high continuous torque is required. The unit is compatible with Allison transmissions equipped with or without a cooler, retarder, or both.Parts Manual: Chelsea 890 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.
