M/T Mainshaft Assembly Clearance Inspection
NOTE: If replacement is required, always replace the synchro sleeve and synchro hub as a set.
  1. Support the bearing inner race with an appropriate sized socket (A), and push down on the mainshaft (B).
  1. Measure 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 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 (0.941−0.944 in.)
    Service Limit:
    23.80 mm (0.937 in.)

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

  1. Measure length (1) of the distance collar as shown.
    • If the length (1) is not within the standard, replace the 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 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 (0.941−0.944 in.)
    Service Limit:
    23.80 mm (0.937 in.)

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

  1. Measure length (2) of the distance collar as shown.
    • If the length (2) is not within the standard, replace the 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 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 (0.941−0.944 in.)
    Service Limit:
    23.80 mm (0.937 in.)

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

  1. Measure 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 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.
    Standard:
    23.92−23.97 mm (0.941−0.944 in.)
    Service Limit:
    23.80 mm (0.937 in.)