The Chelsea 890 Series Power Take-Off, part number 890TAFJW-B5AF or 890TAFJWB5AF, is a hydraulic hot-shift PTO engineered specifically for Allison 3000 MD and 4000 HD Series transmissions. The 890 Series mounts via a 10-bolt pattern and relocates the pump output to the rear of the transmission, improving clearance between the pump and the frame rail. A one-piece main shaft eliminates the input splines found in a conventional PTO-plus-extension arrangement, and the clutch sits at the rear of the housing so the gear section tucks tightly against the transmission. The SAE C output uses Wet Spline Technology to extend shaft and pump spline service life in demanding duty cycles. Continuous-duty torque is rated up to 670 lb-ft, with shaft power reaching 128 HP at 1,000 RPM. Common applications include aerial trucks, fire and rescue apparatus, refuse trucks, and truck cranes. Call us to confirm proper fit for your specific vehicle and transmission configuration.
Features
Fits Allison 3000 MD and 4000 HD Series transmissions
Hydraulic PowerShift (hot-shift) engagement
10-bolt mounting with SAE C output flange and XS-style output shaft
One-piece main shaft eliminates input splines between PTO and output extension
Wet Spline output extends PTO and pump spline life in demanding conditions
Continuous-duty torque up to 670 lb-ft; shaft power 64 HP at 500 RPM, 128 HP at 1,000 RPM
Tech Specs
- Product Series: 890
- Transmission Application: Allison 3000 MD and 4000 HD Series (Input Gear Designator: FJ)
- Mounting Type: 10-Bolt
- Shift Type: Hydraulic PowerShift (hot-shift)
- Output Shaft Type: SAE C (XS) Output
- Outlet Flange Type: SAE C
- Lubricant: Wet Spline (W)
- 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 is a single-unit design, not a PTO with a separate extension. The clutch is positioned at the rear of the PTO housing, allowing the gear section to seat tightly against the transmission for maximum frame-rail clearance. A rear-of-transmission support bracket is included in addition to the standard side-mount PTO interface. The 890 Series is suited for transmissions equipped with or without a cooler or retarder, or both. Typical applications include aerial trucks, fire and rescue trucks, refuse trucks, pumper cleaners, and truck cranes. Part number 890TAFJW-B5AF is also referenced as SP890TAFJW-B5AF. Sold by Pro Gear and Transmission.Parts Manual: Chelsea 890 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.
