Ford 2003 Mustang Workshop Manual page 2901

5. Remove the reverse idler gear.
6. NOTE: If the countershaft extension bearing was installed new, install a new bearing cup.
Remove the reverse idler gear needle bearing and countershaft extension bearing cup.
Inspect the needle bearing for wear or damage. Install a new bearing as necessary.
Inspect the bearing cup for wear or damage. Install a new bearing and bearing cup as
necessary.
7. Remove the reverse idler gear thrust washer and the reverse idler gear shaft.
8. Remove the countershaft extension bearing shim and the fluid funnel.