The Chelsea 890MDFJW-B5AF or 890MDFJWB5AF is a hydraulic hot-shift power take-off engineered for Allison 3000 MD and 4000 HD Series transmissions. Part of the Chelsea 890 Series, it mounts at the side of the transmission using a 10-bolt pattern and positions the pump output to the rear of the transmission, gaining clearance where space is tight between the transmission and frame rail. The output is an SAE C (XS) flange with Wet Spline technology to protect both the PTO and pump shaft splines under continuous operation. Continuous-duty torque reaches up to 670 ft-lb, with intermittent ratings above 501 lb-ft. Shaft power is 64 HP at 500 RPM and 128 HP at 1,000 RPM. Common applications include fire and rescue trucks, aerial trucks, truck cranes, and refuse vehicles. Call us to confirm proper fit for your specific Allison transmission configuration.
Features
Fits Allison 3000 MD and 4000 HD Series transmissions via 10-bolt mounting
Hydraulic hot-shift (PowerShift) engagement
SAE C (XS) output with Wet Spline technology for extended PTO and pump shaft life
Continuous-duty torque up to 670 ft-lb; intermittent torque rated above 501 lb-ft
Shaft power: 64 HP at 500 RPM, 128 HP at 1,000 RPM
One-piece main shaft design moves pump mounting flange to rear of transmission for improved clearance
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) with Wet Spline
- Outlet Flange Type: SAE C
- 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
- Lubricant: Wet Spline
Additional Information
The Chelsea 890 Series is a single-unit design, not a PTO with a bolt-on extension. The main shaft is one-piece, eliminating the input splines between the PTO body and the output extension. The clutch is positioned at the rear of the housing so the gear section tucks tightly against the transmission for maximum clearance. An additional support bracket at the rear of the transmission supplements the standard side-mount bolting pattern. The 890 Series can be ordered for transmissions equipped with or without a cooler, a retarder, or both. Typical markets include aerial, fire and rescue, refuse, truck crane, snow and ice, on-highway, and defense applications.Parts manual and diagrams: Chelsea 890 Series PTO parts list with prices
