M/T Mainshaft Assembly Clearance Inspection
  1. Support the bearing inner race with an appropriate sized socket (A), and push down on the mainshaft (B).
  1. Measure the clearance between 2nd gear (C) and 3rd gear (D) with a feeler gauge (E).
    • If the clearance is more than the service limit, go to Step 3 .
    • If the clearance is within the service limit, go to Step 4 .
    Standard:
    0.06−0.16 mm (0.002−0.006 in.)
    Service Limit:
    0.25 mm (0.010 in.)

  1. Measure the thickness of 3rd gear.
    • If the thickness is less than the service limit, replace 3rd gear.
    • If the thickness is within the service limit, replace the 3rd/4th synchro hub and 3rd/4th synchro sleeve as a set.
    Standard:
    23.92−23.97 mm (0.942−0.944 in.)
    Service Limit:
    23.80 mm (0.937 in.)

R20A3 engine model
K24Z3 engine model
  1. Measure the clearance between 4th gear (A) and the distance collar (B) with a dial indicator (C).
    • If the clearance is more than the service limit, go to Step 5 .
    • If the clearance is within the service limit, go to Step 7 .
    Standard:
    0.06−0.16 mm (0.002−0.006 in.)
    Service Limit:
    0.25 mm (0.010 in.)

  1. Measure the length (1) of the 4th/5th gear distance collar as shown.
    • If the length (1) is not within the standard, replace the 4th/5th gear distance collar.
    • If the length (1) is within the standard, go to Step 6 .
    Standard:
    24.03−24.08 mm (0.946−0.948 in.)

  1. Measure the thickness of 4th gear.
    • If the thickness is less than the service limit, replace 4th gear.
    • If the thickness is within the service limit, replace the 3rd/4th synchro hub and 3rd/4th synchro sleeve as a set.
    Standard:
    23.92−23.97 mm (0.942−0.944 in.)
    Service Limit:
    23.80 mm (0.937 in.)

R20A3 engine model
K24Z3 engine model
  1. Measure the clearance between the distance collar (A) and 5th gear (B) with a dial indicator (C).
    • If the clearance is more than the service limit, go to Step 8 .
    • If the clearance is within the service limit, go to Step 10 .
    Standard:
    0.06−0.16 mm (0.002−0.006 in.)
    Service Limit:
    0.25 mm (0.010 in.)

  1. Measure the length (2) of the 4th/5th gear distance collar as shown.
    • If the length (2) is not within the standard, replace the 4th/5th gear distance collar.
    • If the length (2) is within the standard, go to Step 9 .
    Standard:
    24.03−24.08 mm (0.946−0.948 in.)

  1. Measure the thickness of 5th gear.
    • If the thickness is less than the service limit, replace 5th gear.
    • If the thickness is within the service limit, replace the 5th/6th synchro hub and 5th/6th synchro sleeve as a set.
    Standard:
    23.92−23.97 mm (0.942−0.944 in.)
    Service Limit:
    23.80 mm (0.937 in.)

  1. Measure the clearance between 6th gear (A) and the angular ball bearing (B) with a feeler gauge (C). If the clearance is more than the service limit, go to Step 11 .

    R20A3 Engine Model:

    Standard:
    0.06−0.16 mm (0.002−0.006 in.)
    Service Limit:
    0.25 mm (0.010 in.)


    K24Z3 Engine Model:

    Standard:
    0.15−0.25 mm (0.006−0.010 in.)
    Service Limit:
    0.34 mm (0.013 in.)

  1. Measure the length of the 6th gear distance collar.
    • If the length is not within the standard, replace the 6th gear distance collar.
    • If the length is within the standard, go to Step 12 .
    Standard:
    24.03−24.08 mm (0.946−0.948 in.)

  1. Measure the thickness of 6th gear.
    • If the thickness is less than the service limit, replace 6th gear.
    • If the thickness is within the service limit, replace the 5th/6th synchro hub and 5th/6th synchro sleeve as a set.

    R20A3 Engine Model:

    Standard:
    23.92−23.97 mm (0.942−0.944 in.)
    Service Limit:
    23.80 mm (0.937 in.)


    K24Z3 Engine Model:

    Standard:
    23.83−23.88 mm (0.938−0.940 in.)
    Service Limit:
    23.71 mm (0.933 in.)