The Mack CRD92 front drive differential carries part number RBT-CRD92-3.87 or CRD92R387 and is built around a 3.87 ring-and-pinion ratio. Before placing your order, have the following details ready: fine or coarse spline on the input and output shafts, whether your upper torque rod uses a single tapered ball stud hole or a two-bolt dog-bone style, whether the rear of the differential housing has four 3/4" bolt holes for a transverse rod mounting plate around the rear through-shaft, and your axle spline count. These variables determine exact fitment on Mack front drive axle applications. Call us to confirm the correct configuration for your truck before ordering.

• Ratio: 3.87

This differential is sold on an exchange basis. A core charge will apply at time of purchase and may be refunded in whole or in part following delivery and inspection of the returned core unit. Core returns are subject to the manufacturer core policy unless otherwise agreed in writing. Contact Pro Gear and Transmission for details on the core return process and to arrange a freight quote.