M/T Mainshaft Assembly Clearance Inspection

NOTE: If replacement is required, always replace the synchro sleeve and hub as a set.

1.Support the bearing inner race with an appropriate sized socket (A), and push down on the mainshaft (B).

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

 

2.Measure the clearance between 2nd (C) and 3rd (D) gears with a feeler gauge (E).

  • If the clearance is more than the service limit, go to 3.
  • If the clearance is within the service limit, go to 4.

3.Measure the thickness of 3rd gear.

  • If the thickness of 3rd gear is less than the service limit, replace 3rd gear with a new one.
  • If the thickness of 3rd gear is within the service limit, replace the 3rd/4th synchro hub with a new one.

Standard: 23.92-23.97 mm
(0.981-0.944 in.)
 
Service Limit: 23.80 mm (0.937 in.) 

 

4.Measure the clearance between 4th gear (A) and the spacer collar (B) with a dial indicator (C). If the clearance is more than the service limit, go to 5.

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

 

5.Measure distance (1) on the distance collar.

  • If distance (1) is not within the standard, replace the distance collar with a new one.
  • If distance (1) is within the standard, go to 6.

Standard: 24.03-24.08 mm
(0.946-0.947 in.)
 

 

6.Measure the thickness of 4th gear.

  • If the thickness of 4th gear is less than the service limit, replace 4th gear with a new one.
  • If the thickness of 4th gear is within the service limit, replace the 3rd/4th synchro hub with a new one.

Standard: 23.92-23.97 mm
(0.981-0.944 in.)
 
Service Limit: 23.80 mm (0.937 in.) 

 

7.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 8.

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

 

8.Measure distance (2) on the distance collar.

  • If distance (2) is not within the standard, replace the distance collar with a new one.
  • If distance (2) is within the standard, go to 9.

Standard: 24.03-24.08 mm
(0.946-0.947 in.)
 

 

9.Measure the thickness of 5th gear.

  • If the thickness of 5th gear is less than the service limit, replace 5th gear with a new one.
  • If the thickness of 5th gear is within the service limit, replace the 5th synchro hub with a new one.

Standard: 23.92-23.97 mm
(0.981-0.944 in.)
 
Service Limit: 23.80 mm (0.937 in.) 

 

10.Measure the thickness of the MBS distance collar.

  • If the thickness of MBS distance collar is not within standard, replace the MBS distance collar with a new one.

Standard: 23.95-24.05 mm
(0.943-0.947 in.)