9 Inch 31 Spline Posi Unit - Trac Lok Loc - Traction Lock Fit for All Ratios Designed for all 9 inch 31 spline axles with OE numbers D4TZ4026A, 542036, 913A586, F9-31-TLNF.This clutch-type posi differential is a direct replacement unit featuring a 4 pinion design and includes 1-1/4 inch long ring gear bolts.The unit is built with 45Steel and 20CrMnTi materials for and performance.Silver in color, it is intended for rear vehicle placement. The helical cut gear system enables smooth and consistent power delivery while enhancing traction and vehicle control.It effectively distributes power to both wheels, improving grip across various road conditions.Each unit is tested under extreme conditions to heat resistance and extended service life. Package includes: 1x Differential This is not an part.All brand mentions are used strictly for compatibility reference.