The Chelsea 890 Series Power Take-Off, part number 890LAFJW-D5AZ or 890LAFJWD5AZ, is a hydraulic hot-shift PTO engineered specifically for Allison 3000 MD and 4000 HD Series transmissions. The 890 Series design relocates the pump mounting flange to the rear of the transmission, fitting tightly between the transmission and the frame rail to provide practical pump clearance without an extension piece. The main shaft is a single one-piece unit, eliminating the input splines between the PTO and the output extension. A wet-spline output extends pump shaft life under demanding duty cycles. The unit mounts via a 10-bolt pattern with an SAE C flange output and engages via hydraulic PowerShift. Continuous-duty torque reaches 670 ft-lb, with intermittent torque rated at 501+ ft-lb. Shaft power output is 64 HP at 500 RPM and 128 HP at 1000 RPM. Common applications include aerial trucks, fire and rescue, refuse trucks, and truck cranes. Available from Pro Gear and Transmission. Call us to confirm proper fit for your specific vehicle and transmission configuration.
Features
Fits Allison 3000 MD and 4000 HD Series transmissions via 10-bolt mounting
Hydraulic PowerShift (hot-shift) engagement
SAE C (XS) output shaft with wet-spline technology for extended pump shaft 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 1000 RPM
One-piece main shaft design moves pump flange to rear of transmission for improved clearance without a separate extension
Tech Specs
- Transmission Application: Allison 3000 MD and 4000 HD Series
- Product Series: 890
- Mounting Type: 10-Bolt
- Shift Type: Hydraulic PowerShift (hot-shift)
- Output Shaft Type: SAE C (XS)
- Outlet Flange Type: SAE C
- Lubricant: 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 1000 RPM
Additional Information
The Chelsea 890 Series is a single-unit PTO, not a PTO with a bolt-on extension. The clutch is positioned at the rear of the housing, allowing the gear section to sit flush against the transmission for a tighter fit between the transmission and frame rail. This design is suited for vehicles where pump clearance is critical, including aerial platforms, fire and rescue apparatus, snow and ice trucks, and refuse vehicles. The 890 Series accommodates transmissions equipped with or without a cooler or retarder. The wet-spline output reduces wear on both the PTO and pump shaft in high-cycle, high-demand applications. An additional support bracket at the rear of the transmission is included for structural stability despite the rear-mounted output location.Parts Manual: Chelsea 890 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.
