• Many worn servo pin bores cannot be repaired


Many case servo pin bores sustain scoring and wear damage, but it has not been possible to index or fixture tooling as required to repair a wide variety of servo bores.


The Sonnax servo pin bore reaming fixture has been designed to provide a highly adaptable rigid mounting method that will locate and maintain the correct tool positioning required to repair servo pin bores in a wide range of transmissions.


Tool kit S-96872-TL is no longer in production. Check with your distributor for availability.

Servo Pin Bore Reaming Fixture

Fixture for use with S-56361J-TL, S-76890-TL24, & S-96872-TL tool kits.

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Wear and scoring of servo pin bores is a common problem in many automatic transmissions. In many instances, shift concerns and part failures due to leakage caused by the wear could only be corrected by replacing the case, because there was no way to locate and maintain tool concentricity with the pin bore centerline. The Sonnax servo pin bore reaming fixture establishes a rigid pilot for bore repair tooling. The fixture mounts to the case, and has a floating bearing guide to ensure proper pin centerline. This tool pilots off the OE pin bore, so reaming is not affected by irregular piston or seal concentricity issues.

The SERVO-FIX has been designed to offer a variety of mounting options for a wide range of transmission cases and multiple bores for each case, where required. Special tooling has been designed to work with the fixture to prepare the bore for whichever bore repair kit is required for the individual servo bore being serviced.

  • One rigid fixture adapts to many cases and applications
  • Pilot and reamer align from pin bore centerline, not servo piston bore
  • Salvages expensive cases

Sonnax has designed special tool kits to service a specific servo pin bore, and they must be used in conjunction with the Servo Pin Bore Reaming Fixture, SERVO-FIX. Part numbers for these specially designed tool kits begin with an S to distinguish them from both the F-series tools that work with the VB-FIX, and the traditional Sonnax tool kits.

  • Clamp Mounting Plate
  • Clamp Plate
  • Outer Races (2)
  • Inner Race
  • Studs (3)
  • Washers (3)
  • Wing Nuts (3)
  • Hardware Mounting Kit
  • Base Plate
  •  Servo Pin Bore Reaming Fixture SERVO-FIX


Cleaning & Care Techniques for Sonnax Reamers