The Chelsea 890 Series Power Take-Off (part number 890NHFJW-B3CF or 890NHFJWB3CF) 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 delivers an SAE C ("XS") output flange. The 890 Series relocates the pump mounting flange to the rear of the transmission, giving the pump room to breathe without the need for a separate extension. The main shaft is a single one-piece design, eliminating input splines between the PTO body and the output. A wet-spline output lubricates the pump shaft interface under load. Continuous-duty torque capacity for this series reaches 670 ft-lb; intermittent rating is 501+ ft-lb. Shaft power output is 64 HP at 500 RPM and 128 HP at 1,000 RPM. Common applications include fire and rescue trucks, aerial work trucks, refuse trucks, and truck cranes. Call us to confirm the correct fit for your specific Allison-equipped chassis.
Features
Fits Allison 3000 MD and 4000 HD Series transmissions via 10-bolt mounting
Hydraulic PowerShift (hot shift) engagement for on-the-fly PTO operation
SAE C ("XS") output flange with wet-spline lubrication to extend shaft life
One-piece main shaft eliminates input splines between PTO body and output extension
Pump flange positioned at the rear of the transmission for improved clearance
Continuous-duty torque rating up to 670 ft-lb; shaft power 64 HP at 500 RPM and 128 HP at 1,000 RPM
Tech Specs
- Transmission Fit: 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") Output
- Outlet Flange Type: SAE C
- Lubricant/Spline: 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 1,000 RPM
Additional Information
The Chelsea 890 Series mounts like a standard side-mounted PTO but adds a bracket at the rear of the transmission for extra support. It is a single integrated unit, not a PTO paired with a bolt-on extension, and the clutch sits at the rear of the housing so the gear section tucks tightly against the transmission case. This layout is particularly useful on aerial trucks, fire and rescue apparatus, snow and ice equipment, and any application where pump space is limited and high continuous torque is required. The 890 Series can be spec'd for transmissions with or without a cooler, retarder, or both. Not sure this configuration matches your truck? Give us a call and we will help you confirm the right part.Parts Manual: Chelsea 890 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.
