Allison Transmission’s 4000 Series is designed to make heavy-duty vehicles operate smoothly and efficiently. With close or wide ratio gearing and up to seven speeds available including two overdrive ratios and a second reverse gear, Allison’s 4000 Series is built for productivity and reliability. Ratings up to a maximum of 597 kW (800 hp) are offered. An engine-driven Power Take-Off (PTO) provision and integral output retarder that provides enhanced vehicle braking and reduces brake wear are optional. Allison’s 4000 Series includes 5th Generation advanced electronic controls enhance operation and prognostics capabilities. The 4000 Series delivers both performance and fuel efficiency.