Recessed Thread Repair

Courtesy of GENERAL MOTORS COMPANY

When installed to the proper depth, the flange of the insert (1) will be seated against the counterbore (2) of the drilled/tapped hole.

1. Courtesy of GENERAL MOTORS COMPANY

   Install a stop collar (2) on the counterbore drill (1), if required.

2. Courtesy of GENERAL MOTORS COMPANY

   NOTE:

   • During the drilling process, it is necessary to repeatedly remove the drill and clean chips from the hole and the flutes of the drill.
   • Drill the hole until the stop collar contacts the surface of the base material.

   Drill out the threads of the damaged hole.

3. Courtesy of GENERAL MOTORS COMPANY

   NOTE:

   All chips must be removed from the drilled hole prior to tapping.

   Using compressed air, clean out any chips.

4. Courtesy of GENERAL MOTORS COMPANY

   NOTE:

   • During the tapping process, it is necessary to repeatedly remove the tap and clean chips from the hole and the flutes of the tap.
   • Ensure the tap has created full threads at least to the depth equal to the insert length.

   Using a suitable tapping wrench, tap the threads of the drilled hole by hand only.

5. Courtesy of GENERAL MOTORS COMPANY

   NOTE:

   All chips must be removed from the tapped hole prior to insert installation.

   Using compressed air, clean out any chips.

6. Courtesy of GENERAL MOTORS COMPANY

   Spray cleaner into the tapped hole. Refer to Adhesives, Fluids, Lubricants, and Sealers for recommended cleaner.

7. Courtesy of GENERAL MOTORS COMPANY

   NOTE:

   All chips must be removed from the tapped hole prior to insert installation.

   Using compressed air, clean out any chips.

8. Courtesy of GENERAL MOTORS COMPANY

   NOTE:

   Do not allow oil or other foreign material to contact the outside diameter (OD) of the insert.

   Lubricate the threads of the driver installation tool (2) with the EN 42385-110 (1).

9. Courtesy of GENERAL MOTORS COMPANY

   Install the insert (2) onto the driver installation tool (1).

10. Courtesy of GENERAL MOTORS COMPANY

    Apply threadlock sealant, EN - 42385-109  , LOCTITE 277® or equivalent (1) to the insert OD threads (2). Refer to Adhesives, Fluids, Lubricants, and Sealers for recommended sealant.

11. Courtesy of GENERAL MOTORS COMPANY

    Install the insert (2) into the tapped hole by hand only.

12. Courtesy of GENERAL MOTORS COMPANY

    NOTE:

    If the insert will not thread down until the flange contacts the counterbored surface remove the insert immediately with a screw extracting tool and inspect the tapped hole for any remaining chips and/or improper tapping.

    Install the insert until the flange (2) of the insert contacts the counterbored surface.

13. Courtesy of GENERAL MOTORS COMPANY

    NOTE:

    The driver installation tool will tighten up before screwing completely through the insert. This is acceptable. The threads at the bottom of the insert are being formed and the insert is mechanically locking the insert into the base material threads.

    Continue to rotate the driver installation tool (1) through the insert (2).

14. Courtesy of GENERAL MOTORS COMPANY

    Inspect the insert (1) for proper installation (2) into the tapped hole.

15. Courtesy of GENERAL MOTORS COMPANY

    Any installed insert that restricts or blocks an oil or engine coolant passage (3) will need to have the oil or engine coolant passage drilled out (4) to the original size of the oil or engine coolant passage. After drilling the restriction or blockage, clean out any chips and thread the installation driver tool through the insert again to remove any burrs caused by the drilling of the oil or engine coolant passage.