Main Cap Bolt Hole Thread Repair

Courtesy of GENERAL MOTORS COMPANY

The main cap bolt hole thread repair kit consists of the following items:

• EN-42385-101  Drill (1)
• EN-42385-102  Tap (2)
• EN-42385-103  Driver (3)
• EN-42385-307  Bushing (8)
• EN-42385-308  Alignment Pin (7)
• EN-42385-309  Long Bolt (5)
• EN-42385-310  Short Bolt (6)
• EN-42385-316  Sleeve - Not Shown
• J-42385-306  Fixture Plate (4)

1. Courtesy of GENERAL MOTORS COMPANY

   Position the J-42385-306  Fixture Plate and EN-42385-307  Bushing over the hole that is to be repaired.

2. Position the EN-42385-308  Alignment Pin in the desired hole and install and tighten the EN-42385-309  Long Bolt and EN-42385-310  Short Bolt.

3. Courtesy of GENERAL MOTORS COMPANY

   The outer bolt hole locations 11 - 20 have the shallower counterbores. Use the EN-42385-316  Sleeve with the EN-42385-101  Drill.

4. Drill out the damaged hole until the stop collar of the EN-42385-101  Drill or the EN-42385-316  Sleeve contacts the top of the EN-42385-307  Bushing.
5. Using compressed air, clean out any chips.

6. Courtesy of GENERAL MOTORS COMPANY

   Using a tap wrench and EN-42385-102  Tap, tap the threads of the drilled hole to the proper depth, by rotating the EN-42385-102  Tap into the hole until the mark on the EN-42385-102  Tap aligns with the top of the bushing.

   • For the deeper main cap holes 1 - 10, rotate the EN-42385-102  Tap until the upper mark (4) on the EN-42385-102  Tap aligns with the top of the EN-42385-307  Bushing (3).
   • For the shallower main cap holes 11 - 20, rotate the EN-42385-102  Tap until the lower mark (1) on the EN-42385-102  Tap aligns with top of the EN-42385-307  Bushing (3).
7. Using compressed air, clean out any chips.
8. Spray cleaner into the hole. Adhesives, Fluids, Lubricants, and Sealers
9. Using compressed air, clean any cutting oil and chips out of the hole.

10. Courtesy of GENERAL MOTORS COMPANY

    NOTE:

    Do not allow oil or foreign material to contact the OD of the insert.

    Lubricate the threads of the EN-42385-103  Driver (2) with the driver oil (1). Adhesives, Fluids, Lubricants, and Sealers

11. Courtesy of GENERAL MOTORS COMPANY

    Install the insert (2) onto the EN-42385-103  Driver (1).

12. Courtesy of GENERAL MOTORS COMPANY

    Apply threadlock to the insert OD threads (2). Adhesives, Fluids, Lubricants, and Sealers

13. Courtesy of GENERAL MOTORS COMPANY

    NOTE:

    • The J-42385-306  Fixture Plate (1) and EN-42385-307  Bushing (2) remains installed onto the engine block during the insert installation procedure.
    • The EN-42385-103  Diver (3) 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.

    Install the insert and EN-42385-103  Driver (3) through the J-42385-306  Fixture Plate (1) and the EN-42385-307  Bushing (2) into the hole.

14. Rotate the EN-42385-103  Driver (3) until the mark on the EN-42385-103  Driver (3) aligns with the top of the EN-42385-307  Bushing (2).