Ford 2003 Mustang Workshop Manual page 2889

11. Using the special tool, remove the countershaft extension bearing.
12. Inspect the countershaft and countershaft extension.
Check the shaft surface for wear or damage. Install a new shaft as necessary.
Check the gear teeth for wear, pitting, scoring, spalling or fractures. Install new
components as necessary.
13. Disassemble the fifth/sixth gear synchronizer assembly.
14. Inspect the fifth/sixth synchronizer.
Check for worn, nicked or broken teeth. Install a new synchronizer as necessary.
Check keys for wear or distortion. Install a new synchronizer as necessary.
Check springs for distortion. Install a new synchronizer as necessary.
15. Inspect the fifth/sixth synchronizer blocking rings.
Check for wear or damage. Install new synchronizer blocking rings as necessary.
Check the clearance between the synchronizer blocking ring and the gear.
Position the blocking ring onto the gear. Make sure the correct blocking ring is
measured with the correct gear and that the blocking ring is fully seated on the