Thread Repair

General Thread Repair

Object Number: 320675  Size: SH

The thread repair process involves a solid, thin walled, self-locking, carbon steel, bushing type insert (1). During the bushing installation process, the driver tool expands the bottom external threads of the insert into the base material (2). This action mechanically locks the insert in place. Also, when installed to the proper depth, the flange of the insert will be seated against the counterbore of the repaired hole.

    Caution

    Refer to Safety Glasses Caution in Cautions and Notices.


    Object Number: 320670  Size: SH

    Important

  1. Drill out the threads of the damaged hole (1).
  2. Using compressed air, clean out any chips.
    Object Number: 320672  Size: SH

  3. Counterbore the hole to the full depth permitted by the tool (1).
  4. Using compressed air, clean out any chips.
    Object Number: 320670  Size: SH

  5. Using a tap wrench (2), tap the threads of the drilled hole.
  6. Using compressed air, clean out any chips.
  7. Spray cleaner GM P/N 12346139 (Canadian P/N 10953463), GM P/N 12377981 (Canadian P/N 10953463) or equivalent into the hole.
  8. Using compressed air, clean any cutting oil and chips out of the hole.
    Object Number: 313562  Size: SH

    Important

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

  9. Lubricate the threads of the installer tool (2) with the driver oil (1).
    Object Number: 313567  Size: SH

  10. Install the insert (2) onto the driver tool (1).
    Object Number: 313572  Size: SH

  11. Apply threadlock LOCTITE™ 277, J 42385-109 (1), or equivalent to the insert OD threads (2).
    Object Number: 320673  Size: SH

  12. Install the insert (2) into the hole. Install the insert until the flange of the insert contacts the counterbored surface. Continue to rotate the installer tool (1) through the insert. The installer tool will tighten up before screwing completely through the insert. This is acceptable. You are forming the bottom threads of the insert and mechanically locking the insert to the base material threads.
    Object Number: 320675  Size: SH

  13. Inspect the insert for proper installation into the hole. A properly installed insert (1) will be either flush or slightly below flush with the surface of the base material (2).
Cylinder Head Bolt Hole Thread Repair

    Object Number: 313560  Size: MH

  1. The cylinder head bolt hole thread repair kit consists of the following items:
    Object Number: 260150  Size: SH

    Important

    First design engine blocks have different drill and tap depths using both medium length 100 mm (3.94 in) and long 155 mm (6.1 in) M11 cylinder head bolts. Second design engine blocks use only the medium length 100 mm (3.94 in) bolt with a common drill and tap depth.

  2. Measure the depth of the cylinder head bolt holes (1-10) to determine the proper drill and tap depths. Refer to Thread Repair Specifications .

    Caution

    Refer to Safety Glasses Caution in Cautions and Notices.


    Object Number: 313574  Size: SH

    Important

  3. Install the fixture plate (3), bolts (1), and bushing (2) onto the engine block deck. Position the fixture plate and bushing over the hole that is to be repaired (4).
    Object Number: 313577  Size: SH

  4. Position the alignment pin (1) through the bushing and into the hole.
  5. With the alignment pin in the desired hole, tighten the fixture retaining bolts (2).
  6. Remove the alignment pin from the hole.
    Object Number: 313570  Size: SH

  7. Install the sleeve (2) onto the drill (1), if required.
    Object Number: 309861  Size: SH

    Important

    During the reaming process, it is necessary to repeatedly remove the drill and clean the chips from the hole.

  8. Drill out the threads of the damaged hole. Drill the hole until the stop collar of the drill bit or the sleeve contacts the bushing.
  9. Using compressed air, clean out any chips.
    Object Number: 320667  Size: SH

  10. Using a tap wrench, tap the threads of the drilled hole.
    Object Number: 377637  Size: SH

  11. In order to tap the new threads to the proper depth, rotate the tap into the hole until the marks (1 or 4) on the tap align with the top of the drill bushing (3). For the deeper cylinder head bolt holes, rotate the tap until the upper mark on the tap (4) aligns with the top of the drill bushing. For the shallower cylinder head bolt holes, rotate the tap until the lower mark on the tap (1) aligns with the top of the drill bushing.
  12. Remove the fixture plate (2), bushing (3), and bolts.
  13. Using compressed air, clean out any chips.
  14. Spray cleaner GM P/N 12346139 (Canadian P/N 10953463), GM P/N 12377981 (Canadian P/N 10953463) or equivalent into the hole.
  15. Using compressed air, clean any cutting oil and chips out of the hole.
    Object Number: 313562  Size: SH

    Important

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

  16. Lubricate the threads of the installer tool (2) with the driver oil (1).
    Object Number: 313567  Size: SH

  17. Install the insert (2) onto the driver tool (1).
    Object Number: 313572  Size: SH

  18. Apply threadlock LOCTITE™ 277, J 42385-109 (1), or equivalent to the insert OD threads (2).
    Object Number: 320669  Size: SH

  19. Install the insert and driver (1) into the hole. Rotate the driver tool until the mark on the tool aligns with the deck surface of the engine block. The installer tool will tighten up before screwing completely through the insert. This is acceptable. You are forming the bottom threads of the insert and mechanically locking the insert to the base material threads.
Main Cap Bolt Hole Thread Repair

    Object Number: 313556  Size: MH

  1. The main cap bolt hole thread repair kit consists of the following items:
    Object Number: 377630  Size: SH

  2. Install the fixture plate, bolt, and bushing, onto the engine block. Position the fixture plate and bushing over the hole that is to be repaired.
  3. Position the alignment pin in the desired hole and tighten the fixture retaining bolts.
    Object Number: 63214  Size: SH

  4. Drill out the damaged hole. The outer bolt hole locations (11-20) have the shallower counterbores. Use sleeve J 42385-316 with the drill. Drill until the stop collar of the drill bit or the sleeve contacts the bushing.
  5. Using compressed air, clean out any chips.
    Object Number: 377637  Size: SH

  6. Using a tap wrench, tap the threads of the drilled hole. In order to tap the new threads to the proper depth, rotate the tap into the hole until the mark on the tap aligns with the top of the bushing. For the deeper main cap holes (1-10), rotate the tap until the upper mark (4) on the tap aligns with the top of the bushing (3). For the shallower main cap holes (11-20), rotate the tap until the lower mark (1) on the tap aligns with top of the bushing (3).
  7. Using compressed air, clean out any chips.
  8. Spray cleaner GM P/N 12346139 (Canadian P/N 10953463) or equivalent into the hole.
  9. Using compressed air, clean any cutting oil and chips out of the hole.
    Object Number: 313562  Size: SH

    Important

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

  10. Lubricate the threads of the installer tool (2) with the driver oil (1).
    Object Number: 313567  Size: SH

  11. Install the insert (2) onto the driver tool (1).
    Object Number: 313572  Size: SH

  12. Apply threadlock LOCTITE™ 277, J 42385-109 (1), or equivalent to the insert OD threads (2).
    Object Number: 377635  Size: SH

    Important

    The fixture plate and bushing remains installed onto the engine block during the insert installation procedure.

  13. Install the insert and driver (1) through the fixture plate and bushing and into the hole. Rotate the driver tool until the mark on the tool (3) aligns with the top of the bushing (2). The installer tool will tighten up before screwing completely through the insert. This is acceptable. You are forming the bottom threads of the insert and mechanically locking the insert to the base material threads.