Ford 2003 Mustang Workshop Manual page 490

1. Attach the special tool.
2. Position the special tool tip centrally on a drive tooth.
3. Zero the indicator.
4. Turn the differential ring gear without turning the drive pinion gear. Record the indicator
reading. The allowable backlash is 0.203 mm ( 0.008 in) to 0.330 mm ( 0.013 in) and
must not very more than 0.1016 mm (0.004 in) between points measured. A backlash
variation of more than 0.1016 mm (0.004 in) between points checked indicates gear/case
runout.
If backlash is within specifications, proceed to Final assembly in this procedure.
To correct for a high or low backlash proceed as follows.
57. To correct for high or low backlash increase the thickness of one differential bearing shim and
decrease the thickness of the other differential bearing shim by the same amount. Refer to the
following tables when adjusting the backlash. When the backlash is within specifications,
proceed to Final assembly in this procedure.
Backlash Change Required Thickness Change Required
mm
0.025
0.050
0.076
0.101
0.127
0.152
0.177
0.203
0.228
0.254
0.279
Inch mm
0.001 0.050
0.002 0.050
0.003 0.101
0.004 0.152
0.005 0.152
0.006 0.203
0.007 0.254
0.008 0.254
0.009 0.304
0.010 0.355
0.011 0.355
Inch
0.002
0.002
0.004
0.006
0.006
0.008
0.010
0.010
0.012
0.014
0.014