The Chelsea 890JBFJW-B3CK or 890JBFJWB3CK is a hydraulic hot-shift power take-off built for Allison 3000 MD and 4000 HD series transmissions. It mounts via a 10-bolt pattern with an SAE C outlet flange and uses a Wet Spline output to reduce wear on the PTO and pump shaft in continuous-duty operation. Continuous-duty torque capacity is up to 670 ft-lb, with intermittent torque ratings starting at 501 ft-lb. The one-piece main shaft eliminates the inter-stage input splines found on conventional PTO-plus-extension setups, and the clutch is positioned at the rear of the housing so the gear section sits tight against the transmission, opening up clearance for pump mounting. At 64 HP at 500 RPM and 128 HP at 1,000 RPM shaft power, this unit suits fire and rescue trucks, aerial platforms, refuse trucks, and truck cranes. Call us to confirm proper fit for your application.
Features
Fits Allison 3000 MD and 4000 HD series transmissions via 10-bolt mounting
Hydraulic hot-shift (PowerShift) engagement
SAE C outlet flange with SAE C (XS) output shaft
Wet Spline output extends PTO and pump shaft service life
Continuous-duty torque capacity up to 670 ft-lb; intermittent torque 501+ ft-lb
Shaft power: 64 HP at 500 RPM, 128 HP at 1,000 RPM
Extended one-piece main shaft locates pump output to the rear of the 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
- Outlet Flange Type: SAE C
- Output Shaft Type: SAE C (XS)
- Lubricant/Output: 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 (500 RPM) / 128 HP (1,000 RPM)
Additional Information
The Chelsea 890 Series was designed specifically to address clearance challenges on Allison 3000 and 4000 series transmissions. Unlike a conventional PTO paired with a bolt-on extension, the 890 is a single assembly with a one-piece main shaft, removing the input splines between the PTO body and the output. The clutch sits at the rear of the unit, allowing the housing and gear section to tuck tightly to the transmission while moving the pump mounting flange rearward for adequate frame-rail clearance. The 890 Series can be configured for transmissions fitted with a cooler, a retarder, or both. Typical applications include aerial trucks, fire and rescue apparatus, snow and ice equipment, refuse trucks, and truck cranes where pump space and sustained high torque are critical requirements. Part number 890JBFJW-B3CK is also referenced as SP890JBFJW-B3CK. Contact Pro Gear and Transmission to verify compatibility with your specific transmission configuration.Parts Manual: Chelsea 890 Series PTO Parts Manual (PDF) — exploded views, item numbers and the full parts breakdown for this series.
