Reverse Idler Gear: Inspection

WARNING: This page is about a different car, the 2012 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.

Move the reverse shifter rod toward the reverse side. Check the clearance between the reverse idler gear and the transmission case wall surface. If out of specification, select the appropriate reverse shifter lever and adjust.
Clearance A:

6.0 - 7.5 mm (0.236 - 0.295 in)

Fig 1: Checking Clearance Between Reverse Idler Gear And Transmission Case
Courtesy of SUBARU OF AMERICA, INC.
After installing a suitable reverse shifter lever, shift into neutral. Check the clearance between the reverse idler gear and the transmission case wall surface. If out of specification, select the appropriate washer and adjust.
Clearance:

0 - 0.5 mm (0 - 0.020 in)

Fig 2: Checking Clearance Between Reverse Idler Gear And Transmission Case Wall Surface
Courtesy of SUBARU OF AMERICA, INC.
Check the reverse idler gear and shaft for damage. Replace if it is damaged.