Ford Super Duty Auto Locking Hub Pair 600-203, 1999-2004

This is a pair of automatic front locking hubs for the 1999-2004 Ford F-250, F-350, F-450 and F-550 Super Duty 4x4 and the 2000-2005 Excursion 4x4. They replace Ford 1C3Z-3B396-CB and cross to Dorman 600-203. Each hub has the factory-style dial with AUTO and LOCK positions and comes with its O-ring seal.

In AUTO, the hub is supposed to engage by itself when the transfer case goes into 4WD and the front axle starts turning. As these hubs age, the internal cam and clutch parts wear and the grease breaks down. The usual complaints are a front end that does not pull in 4WD even though the front driveshaft is turning, a ratcheting or grinding noise from one wheel under load, or a hub that only works when the dial is turned to LOCK. If the truck pulls in LOCK but not in AUTO, the hub is the likely problem, not the transfer case.

To replace one: park on level ground, put the transfer case in 2WD and raise that corner. Remove the hub retaining bolts, pull the old hub off the wheel hub and clean the mating face and splines. Put a light coat of grease on the new O-ring, line the hub up on the splines and start the bolts by hand, then snug them evenly in a crisscross pattern. Test in AUTO and in LOCK before you drive off.

Fitment note: 2005 and newer Super Duty trucks use the vacuum-operated hub lock system and a different hub, so this pair is for the 1999-2004 Super Duty and the 2000-2005 Excursion only. Check the number on your old hub before ordering.