Front Brakes locked after changing Unit Bearings

Symptoms

Your front wheels aren't moving after changing the Unit Bearings or Hub assemblies.

Cause

You may have installed the wrong unit bearings.  XJs changed the Unit Bearing designs and hat depth between early and late model XJs.   If  you install the wrong unit bearing, the brake rotors become bound once you torque everything down.  Here are the correct part numbers for the Wheel bearing / Hub assembies by year:

  1. 1984 through 1989 (early style rotors)
  2. 1990 through mid-1999 (composite rotors 3 3/16H x 1/8D)
    1. Crown Automotive PN 53007449
    2. Moog 513084
    3. Detroit 513084
  3. late-1999 through 2001 (Full cast rotors 3 1/16H x 1/4 to 5/16 Depth)
    1. Moog 513158
    2. Detroit 513158
    3. Timken HA597449

Source:  https://naxja.org/forum/showthread.php?p=243386895