1. Hold the secondary shaft, and measure the 1st gear axial clearance in at least three places while moving the 1st gear (A). Use the average as the actual clearance.

   Standard: | 0.04−0.12 mm (0.002−0.005 in.)

1. If the clearance is out of standard, remove the 40 x 51.5 mm thrust washer and measure its thickness.

1. Select and install a new thrust washer, then recheck.
   THRUST WASHER, 40 x 51.5 mm: K20Z2 Engine Model

   No. | Part Number | Thickness
   --- | --- | ---
   1 | 90503-PRP-000 | 4.80 mm (0.189 in.)
   2 | 90504-PRP-000 | 4.85 mm (0.191 in.)
   3 | 90505-PRP-000 | 4.90 mm (0.193 in.)
   4 | 90506-PRP-000 | 4.95 mm (0.195 in.)
   5 | 90507-PRP-000 | 5.00 mm (0.197 in.)
   6 | 90508-PRP-000 | 5.05 mm (0.199 in.)

   K24A3 Engine Model

   No. | Part Number | Thickness
   --- | --- | ---
   1 | 90503-RCT-000 | 4.80 mm (0.189 in.)
   2 | 90504-RCT-000 | 4.85 mm (0.191 in.)
   3 | 90505-RCT-000 | 4.90 mm (0.193 in.)
   4 | 90506-RCT-000 | 4.95 mm (0.195 in.)
   5 | 90507-RCT-000 | 5.00 mm (0.197 in.)
   6 | 90508-RCT-000 | 5.05 mm (0.199 in.)

1. After replacing the thrust washer, make sure the clearance is within standard.

1. Disassemble the shaft and gears.