Inspection After Disassembly: Synchronizer

WARNING: This page is about a different car, the 2006 Nissan Xterra. However, it is still accessible from the selected car via links, so may be relevant.

If the contact surface on coupling sleeve, synchronizer hub, and shifting insert has damage or abrasion, replace the components.
Coupling sleeve and synchronizer hub shall move smoothly.

Fig 1: Inserting Coupling Sleeve And Synchronizer Hub
Courtesy of NISSAN MOTOR CO., U.S.A.
If the cam surface on bulk ring or contact surface on insert has damage or excessive wear, replace with a new one.
If spread spring damaged, replace with a new one.

Fig 2: Identifying Bulk Ring

Courtesy of NISSAN MOTOR CO., U.S.A.