Drive Pinion Shaft Assembly: Inspection

Disassembled parts should be washed clean first and then inspected carefully.

1. Bearings

   Replace bearings in the following cases:

   • Bearings whose balls, outer races and inner races are broken or rusty.
   • Worn bearings
   • Bearings that fail to turn smoothly or make abnormal noise when turned after gear oil lubrication.
   • The ball bearing on the rear side of the drive pinion shaft should be checked for smooth rotation before the drive pinion assembly is disassembled. In this case, because a preload is working on the bearing, its rotation feels like it is slightly dragging unlike the other bearings.
     Fig 1: Identifying Drive Pinion Shaft & Ball Bearing

     
   • Bearings having other defects
2. Bushing (each gear)

   Replace the bushing in the following cases:

   • When the sliding surface is damaged or abnormally worn.
   • When the inner wall is abnormally worn.
3. Gears
   • Replace gears with new ones if their tooth surfaces are broken, damaged, or excessively worn.
   • Correct or replace if the cone that contacts the baulk ring is rough or damaged.
   • Correct or replace if the inner surface or end face is damaged.
4. Baulk ring

   Replace the ring in the following cases:

   • When the inner surface and end face are damaged.
   • When the ring inner surface is abnormally or partially worn down.
   • If the gap between the end faces of the ring and the gear splined part is excessively small when the ring is pressed against the cone.

     Clearance (A): 

     1. 0.5 - 1.0 mm (0.020 - 0.040 in) 
     Fig 2: Identifying Clearance (A)

     
   • When the contact surface of the synchronizer ring insert is scored or abnormally worn down.
5. Shifting insert key

   Replace the insert if deformed, excessively worn, or defective in any way.

   Fig 3: Identifying Hub & Slider Assembly

   
6. Oil seal

   Replace the oil seal if the lip is deformed, hardened, damaged, worn, or defective in any way.

7. O-ring

   Replace the O-ring if the sealing face is deformed, hardened, damaged, worn, or defective in any way.

8. Gearshift mechanism

   Repair or replace the gearshift mechanism if excessively worn, bent, or defective in any way.

9. Inspect clearance between 1st, 2nd driven gear and reverse driven gear. If any clearance is not within specifications, replace shifter fork as required.

   Clearance (a) and (b): 

   1. 9.5 mm (0.374 in) 
      Fig 4: Identifying 1st, 2nd & Reverse Driven Gears

      
      Fig 5: 1st & 2nd Shifter Fork Chart

      
10. Inspect clearance between 3rd, 4th drive gear and coupling sleeve. If any clearance is not within specifications, replace shifter fork as required.

    Clearance (a) and (b): 

    1. 9.3 mm (0.366 in) 
    Fig 6: Inspecting Clearance Between 3rd, 4th Drive Gear And Coupling Sleeve

    
    Fig 7: 3rd & 4th Shifter Fork Chart

    
11. Inspect clearance between 5th drive gear and coupling sleeve. If any clearance is not within specifications, replace shifter fork as required.

    Clearance (a): 

    1. 9.3 mm (0.366 in) 
    Fig 8: Identifying Clearance Between 5th Drive Gear And Coupling Sleeve

    
    Fig 9: 5th Shifter Fork Chart

    
12. Inspect rod end clearances (A) and (B). If any clearance is not within specifications, replace rod or fork as required.

    Clearance (A): 

    1. 1st - 2nd to 3rd - 4th: 
    2. 0.4 - 1.4 mm (0.016 - 0.055 in) 

    Clearance (B): 

    1. 3rd - 4th to 5th: 
    2. 0.5 - 1.3 mm (0.020 - 0.051 in) 
    Fig 10: Inspecting Rod End Clearances (A) & (B)