2021 Subaru Ascent BaseFACTORY OEM SERVICE PROCEDURE

Differential Case

NOTE: Apply differential gear oil to each sliding part.
  1. Install the differential bevel gear and differential bevel pinion together with the thrust washer, and install the pinion shaft.
  2. Measure the backlash between the differential bevel gear and differential bevel pinion, and select a thrust washer.
    1. Install the ST to the differential case.
      NOTE: The ST is a SUBARU genuine part.

      Preparation tool: 

      ST: Axle shaft (38415AA070)

    2. Measure the backlash between the differential bevel gear and differential bevel pinion using the magnet stand and dial gauge (lever type).
      NOTE:
      • Set the dial gauge (lever type) so that its needle contacts the differential bevel gear tooth.
      • When measuring, fix the differential bevel pinion in place.

      Specification: 

      0.13 - 0.18 mm (0.005 - 0.007 in)

      G13592367Courtesy of SUBARU OF AMERICA, INC.
    3. Select and replace the thrust washer so that the backlash is within the standard.
  3. Align the pinion shaft and differential case holes, and install a new spring pin from the driven gear side.
    G13226021Courtesy of SUBARU OF AMERICA, INC.
  4. Using the ST1 and ST2, install the left and right side bearing inner races.

    Preparation tool: 

    ST1: BUSHING 1-2 INSTALLER (499277100)

    ST2: SEAT (398497701)

    G11256006Courtesy of SUBARU OF AMERICA, INC.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.