Saginaw GMT Steering Gearbox 16:1 Variable Ratio With DD Input Shaft For 2001-Present GM Trucks/SUVs

This is a GM Truck and SUV gearbox that uses the 3 bolt "Triangle" mounting pattern. It is typically found on 1987-Present Chevy’s and GMC’s. It came in multiple variations. When ordering you will need to know the following information: Piston Bore Size There is a casting number on the housing of the gearbox (Either 83 or 84). 83 is a “small bore” (GMT400). 84 is a “big bore” (GMT800). Most of the time: 1500 2X4, 1500 4X4 and 2500 2X4 use the small bore, and 2500 4X4, 3500 2X4 OR 4X4 use the big bore, but there are some exceptions. Blind Spline Most vehicles use a sector shaft with 3 Blind Splines, but some (usually Diesels) have 4 Blind Splines. You will need to know which you have. End Cap Number Some models of vehicles have different internal stops to limit steering travel. There is a number on the end cap that will let us know what stops you need. It is also a good idea to verify your input shaft type. 1987-2000 should have a 3/4-30 splined input shaft and 2001 to present use a DD