The Chelsea 890 Series Power Take-Off, part number 890XBFJW-B5XK or 890XBFJWB5XK, 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 positions the pump output at the rear of the transmission, placing the SAE C output flange where it clears tight frame-rail installations without requiring a separate extension. The main shaft is a one-piece design that eliminates input splines between the PTO and output extension, and Wet Spline Technology lubricates the output continuously for extended pump shaft life. Continuous-duty torque rating reaches 670 lb-ft, with intermittent capacity above 501 lb-ft. Shift is hydraulic PowerShift. Shaft power runs 64 HP at 500 RPM and 128 HP at 1000 RPM. Common applications include aerial trucks, fire and rescue apparatus, refuse trucks, and truck cranes. A genuine Chelsea part from Pro Gear and Transmission. Call us to confirm proper fit for your application.

• Product Series: 890
• Transmission Fitment: Allison 3000 MD and 4000 HD Series (Input Gear Designator: FJ)
• Mounting Type: 10-Bolt
• Shift Type: Hydraulic PowerShift
• Outlet Flange Type: SAE C
• Output Shaft Type: SAE C (XS)
• Continuous Torque: 670 lb-ft (see 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 1000 RPM
• Lubricant/Spline: Wet Spline

The 890 Series mounts like a standard side-mounted PTO but includes an additional bracket at the rear of the transmission for support. The clutch is located at the rear of the PTO housing, allowing the gear section to tuck tightly against the transmission for improved frame-rail clearance. Because it is a single-unit design rather than a PTO paired with a bolt-on extension, the one-piece shaft removes the intermediate input splines that are common failure points under high-torque cycling.
Typical applications where the rear-mounted output and high continuous torque rating are specified include aerial and bucket trucks, fire and rescue pumpers, refuse collection vehicles, and truck cranes. The 890 Series accommodates Allison 3000 and 4000 transmissions configured with or without a cooler, a retarder, or both.
Part number 890XBFJW-B5XK is also referenced as 890XBFJWB5XK.