Ford 2003 Mustang Workshop Manual page 351

16. Rotate the differential several times to verify that the differential bearings have seated correctly.
17. Using the special tools, recheck the backlash.
If backlash is within the specification, refer to Backlash within specification in this
procedure. If backlash is not within the specification, repeat Backlash not within
specification in this procedure.
The specification shown is the full allowable range. For the preferred range, refer to
Specifications in this section.
Backlash within specification
18. Remove the bolts and bearing caps.
19. Set the differential bearing preload.
1. To establish differential bearing preload, increase both left and right differential bearing
shim sizes by the specification shown.
2. Using the special tool, fully seat the differential bearing shims. Make sure the assembly
rotates freely.