Synchronizer Ring

Check that the outer synchronizer ring clutch gear is free of damage.
Check that the synchronizer rings and synchronizer cones are free of damage or wear in the contact surface and broken screw threads.

Fig 1: Locating Synchronizer Rings Contact Surface Area
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Check that the outer synchronizer ring and synchronizer key contact surface is free of damage and wear.
Join the outer and inner synchronizer rings and synchronizer cone together and check clearance "A" shown. If "A" is less than the limit value, replace them.
Limit A (from back of outer ring to clutch gear): 0.5 mm (0.02 inch)

Fig 2: Identifying Outer And Inner Synchronizer Rings
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.