High horsepower levels and heavy-duty use stress transmission parts past what they were originally designed to handle. The Allison’s output shaft is a common failure point so PPE offers this Billet Output Shaft for high-performance transmissions. The PPE shaft has been specially designed to withstand the higher horsepower (over 800 RWHP) and torque levels that come with high-performance engines or the added stress from towing or racing. This shaft is highly recommended when installing our Stage4, Stage5 and Stage6 Transmission Kits.