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 a socket (A), and push down on the mainshaft (B).

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.

Standard: 0.06-0.21 mm
(0.002-0.008 in.)
 
Service Limit: 0.33 mm (0.013 in.) 

 

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: 27.92-27.97 mm
(1.099-1.101 in.)
 
Service Limit: 27.85 mm (1.096 in.) 

 

4.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 5.

Standard: 0.06-0.19 mm
(0.002-0.007 in.)
 
Service Limit: 0.31 mm (0.012 in.) 

 

5.Measure distance (1) on the spacer 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: 24.03-24.06 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: 27.02-27.07 mm
(1.064-1.066 in.)
 
Service Limit: 26.95 mm (1.061 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: 0.06-0.19 mm
(0.002-0.007 in.)
 
Service Limit: 0.31 mm (0.012 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: 24.03-24.06 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: 28.92-28.97 mm
(1.139-1.141 in.)
 
Service Limit: 28.85 mm (1.136 in.) 

 

10.Measure the thickness of the distance collar.

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

Standard: 12.00-12.05 mm
(0.472-0.474 in.)