Three different unit hub/bearing assemblies and matching disk brake rotor types were used during the years 1984-2001 on the XJ D30 axles. (XJ, MJ, TJ, and ZJ, axles can interchange most parts, so the 1999.5 cast/composite info may apply to all). Two different steering knuckle types were used during the years 1984-2001 on XJ D30 axles.
Unit Hub/Bearing Assemblies:
1) 1984 through 1989 - Original AMC hubs ( Jeep Part Numbers 4723371, 5252725, 53000228, 53000234 )
AMC brake rotors, AMC calipers, AMC steering knuckles, and AMC roller bearing hubs.
The unit hub/bearing are the same part number for both sides of the vehicle.
2) 1990 through 1999.5 - Older type unit hubs ( Jeep Part Number 53007449 )
Uses Composite brake rotors and Chrysler calipers and Chrysler steering knuckles.
The unit hub/bearing are the same part number for both sides of the vehicle.
3) 1999.5 through 2001 - New type unit hubs ( TIMKEN Part # HA597449 - Jeep Part Number 5016458 ) Uses Cast brake rotors and Chrysler calipers and Chrysler steering knuckles. The unit hub/bearing are the same part number for both sides of the vehicle.
Steering Knuckles:
1) 1984 to 1989 - AMC Steering Knuckles. Left and right side steering knuckles have different part numbers and only accept AMC calipers.
2) 1990 to 2001 - Chrysler Steering Knuckles. Left and right side steering knuckles have different part numbers and only accept Chrysler calipers.
Any XJ AMC or XJ Chrysler steering knuckle will fit on any XJ D30. Remember, unit hubs type, and brake caliper type, must match the steering knuckle type, Chrysler vs. AMC.
Brake Calipers:
1) 1984 to 1989 - AMC Brake Calipers. Left and right sides calipers have different part numbers and only fit on AMC steering knuckles.
2) 1990 to 2001 - Chrysler Brake Calipers Left and right sides calipers have different part numbers.
AMC and Chrysler calipers do not interchange, they must be mounted on the corresponding AMC or Chrysler steering knuckle.
Brake Rotors:
1) 1984 - 1989 - AMC Brake Rotors
2) 1984 - 1999.5 - Composite Brake Rotors
3) 1999.5 - 2001 - Cast Brake Rotors