Rear Differential: Disassembly

To detect the real cause of trouble, inspect the following items before disassembling.

• Tooth contact of crown gear and pinion, and backlash
• Runout of crown gear at its back surface
• Turning resistance of drive pinion

1. Set the ST on vise and install the differential assembly to ST.

   ST 398217700 ATTACHMENT

   Fig 1: Installing Differential Assembly To ST

   Courtesy of SUBARU OF AMERICA, INC.
2. Drain the gear oil by removing the plug.
3. Remove the air breather cap.
   NOTE:

   • Do not attempt to remove the air breather cap unless necessary.
   • When removing the air breather cap, replace the air breather cap with a new one.
   Fig 2: Removing Air Breather Cap

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4. Remove the rear cover by loosening the retaining bolts.
   Fig 3: Removing Rear Cover By Loosening Retaining Bolts

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5. Make right and left side bearing retainers in order to identify them at reassembly. Remove the side bearing retainer attaching bolts, set the ST to differential case, and extract right and left side bearing retainers with a puller.
   NOTE: Each shim, which is installed to adjust the side bearing preload, should be kept together with its mating retainer.

   ST 398457700 ATTACHMENT

   Fig 4: Removing Right & Left Side Bearing Retainers

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6. Pull out the differential case assembly from differential carrier.
   NOTE: Be careful not to hit the teeth against the case.
   Fig 5: Pulling Out Differential Case Assembly From Differential Carrier

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7. Remove the O-ring from side bearing retainer.
8. Remove the oil seal from side bearing retainer.

   Refer to REPLACEMENT , Rear Differential Side Oil Seal.

9. Pull the bearing cup from side bearing retainer using ST.

   ST 398527700 PULLER ASSY

   Fig 6: Pulling Bearing Cup From Side Bearing Retainer

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10. Extract the bearing cone with ST.
    NOTE:

    • Set the puller so that its claws catch the edge of bearing cone.
    • Never mix up the right and left hand bearing races and cones.

    ST 399527700 PULLER SET

    Fig 7: Extracting Bearing Cone With ST

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11. Remove the crown gear by loosening the crown gear bolts.
    Fig 8: Removing Crown Gear By Loosening Crown Gear Bolts

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12. Drive out the pinion shaft lock pin from crown gear side. (Without LSD)
    NOTE: The lock pin is staked at the pin hole end on the differential carrier; do not drive it out forcibly before unstaking it.

    ST 899904100 STRAIGHT PIN REMOVER

    Fig 9: Driving Out Pinion Shaft Lock Pin From Crown Gear Side (Without LSD)

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13. Draw out the pinion mate shaft and remove the pinion mate gears, side gears and thrust washers. (Without LSD)
    NOTE: The gears as well as thrust washers should be marked or kept separated right and left, front and rear.
    Fig 10: Removing Pinion Mate Gears, Side Gears & Thrust Washers (Without LSD)

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14. Hold the companion flange with ST and remove the drive pinion nut.

    ST 498427200 FLANGE WRENCH

    Fig 11: Removing Drive Pinion Nut

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15. Extract the companion flange with a puller.
    Fig 12: Extracting Companion Flange With Puller

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16. Press the end of drive pinion shaft and extract it together with the rear bearing cone, preload adjusting spacer and washer.
    NOTE: Hold the drive pinion so as not to drop it.

    ST 398467700 DRIFT

    Fig 13: Pressing End Of Drive Pinion Shaft

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17. Remove the rear bearing cone from drive pinion by supporting the cone with ST.
    NOTE: Place the replacer so that its center-recessed side faces the pinion gear.

    ST 398517700 REPLACER

    Fig 14: Removing Rear Bearing Cone From Drive Pinion

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18. Remove the front oil seal from differential carrier using ST.

    ST 398527700 PULLER ASSY

    Fig 15: Removing Front Oil Seal From Differential Carrier

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19. Remove the pilot bearing together with front bearing cone using ST.

    ST 398467700 DRIFT

    Fig 16: Removing Pilot Bearing Together With Front Bearing Cone

    Courtesy of SUBARU OF AMERICA, INC.
20. When replacing the bearings, hit out the front bearing cup and rear bearing cup in this order out of case by using a brass bar.
    Fig 17: Removing Front Bearing Cup & Rear Bearing Cup

    Courtesy of SUBARU OF AMERICA, INC.