Allison 1000 4WD Output Shaft 2001-2010. This shaft is made in-house at TCS for heavy duty towing and competition applications. All TCS shafts are made from Select Grades of Super Strength steel alloys and are approx. 50% stronger than the O.E.M. versions. This 4WD output shaft is made from 300M billet steel. Ideal for heavy duty service applications. Precision ground for high dimensional accuracy. Ideal for those who challenge their vehicles at work or at play.