897 Series

The Chelsea 897 Series Power Take-Off (PTO) is a constant mesh PTO designed for Allison 3000 and 4000 series transmissions, delivering industry-leading performance with torque capacity up to 670 lb-ft. Engineered for tight chassis packaging, it improves clearance by positioning the unit between the transmission and frame rail while routing the pump output toward the rear of the transmission for optimal space utilization. Unlike extension-style configurations, the 897 Series is a fully integrated single-unit design. It features a one-piece main shaft that removes intermediate input splines between the PTO and output section, improving strength and reducing wear points. The pump interface is also located at the rear of the transmission, allowing the housing and gear assembly to sit tightly against the transmission for a compact installation. Wet Spline Technology is incorporated into the output design to help extend PTO and pump shaft life in demanding, continuous-duty applications. The 897 Series is available for transmissions with or without coolers, retarders, or both, providing broad compatibility across vocational configurations. The Chelsea 897 Series PTO is widely used in aerial equipment, fire and rescue vehicles, snow and ice service trucks, defense applications, and other mobile equipment where high torque output and compact installation space are critical.