Diesel Data: Automotive Repair

7. Mainshaft Assembly Clearance Inspection

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).
2. 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 - 0.21 mm (0.002 - 0.008 inch)
Service Limit: 0.30 mm (0.012 inch)





3. 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.





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 step 5.





5. Measure distance (1) on the distance collar.
^ If distance (1) is not within the standard, replace the distance collar.
^ If distance (1) is within the standard, go to step 6.





6. 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.





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 step 8.





8. Measure distance (2) on the distance collar.
^ If distance (2) is not within the standard, replace the distance collar.
^ If distance (2) is within the standard, go to step 9.





9. 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 synchro hub.





10. Measure the thickness of the distance collar.
If the thickness is not within the standard, replace the distance collar.