Main Shaft Assembly: Inspection

Disassembled parts should be washed with cleaning solvent first, then inspected carefully.

1. Bearing

   Replace the bearings in the following cases.

   • When the bearing balls, outer races and inner races are broken or rusty.
   • When the bearing is worn.
   • When the bearings fail to turn smoothly or emit noise in rotation after transmission gear oil has been applied.
   • When bearing has other defects.
2. Bushing (each gear)

   Replace the bushing in following cases.

   • When the sliding surface is damaged or abnormally worn.
   • When the inner wall is abnormally worn.
3. Gear

   Replace gears in the following cases.

   • Replace the gear with new part if its tooth surfaces are broken, damaged or excessively worn.
   • Correct or replace if the cone that contacts the baulk ring is rough or damaged.
   • Repair or replace if the inner surface or end face is damaged.
4. Baulk ring, synchro cone

   Replace the baulk ring and synchro cone in the following cases.

   • When the inner surface or end face is damaged.
   • When the baulk ring inner surface is abnormally or partially worn down.
   • When the contact surface of the baulk ring insert section is cracked or abnormally worn.
   • If the gap between the end faces of the baulk ring and the gear splined part is excessively small, check the clearance (A) while pressing the ring against the cone.

     Clearance (A): 

     0.5 mm (0.020 in) or more

     • Single cone
       Fig 1: Checking Clearance Between End Faces Of Baulk Ring And Gear Splined - Single Cone

       Courtesy of SUBARU OF AMERICA, INC.
     • Double cone
       Fig 2: Checking Clearance Between End Faces Of Baulk Ring And Gear Splined - Double Cone

       Courtesy of SUBARU OF AMERICA, INC.
     • Apply transmission gear oil to the cone of the gear and while press-fitting the baulk ring, check there is no rotation in the circumferential direction.
     Fig 3: Checking Cone Of Gear For No Rotation

     Courtesy of SUBARU OF AMERICA, INC.
5. Coupling sleeve and synchronizer hub
   • Check the slipping condition of the coupling sleeve.
   • Check the splines on the coupling sleeve and synchronizer hub for wear.
6. Shifting insert

   Replace the shifting insert if there is deformation, excessive wear on the ball section or any defectiveness.

   Fig 4: Checking Ball Defectiveness

   Courtesy of SUBARU OF AMERICA, INC.
7. Oil seal

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

8. Gearshift mechanism

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