Inboard Bolt Holes

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

Fig 1: View Of Fixture Plate & Components - Inboard Bolt Holes
Courtesy of GENERAL MOTORS CORP.
1. Position the fixture plate (3) with the bushing (1) installed over the cylinder head bolt hole to be repaired (4).
2. Loosely install the fixture plate bolts (2) into the remaining cylinder head bolt holes.
Fig 2: Positioning Alignment Pin - Inboard Bolt Holes
Courtesy of GENERAL MOTORS CORP.
3. Position the alignment pin (1) through the bushing and into the cylinder head bolt hole.
4. With the alignment pin in the desired cylinder head bolt hole, tighten the fixture retaining bolts (2).
5. Remove the alignment pin (1) from the cylinder head bolt hole.
Fig 3: View Of Stop Collar & Counterbore Drill
Courtesy of GENERAL MOTORS CORP.
6. Install the stop collar (2) onto the drill (1).
Fig 4: Drilling Out Threads Of Damaged Hole - Inboard Bolt Holes
Courtesy of GENERAL MOTORS CORP.
IMPORTANT:
• 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 top of the drill bushing.
7. Drill out the threads of the damaged hole.
Fig 5: Cleaning Out Metal Chips
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: All chips must be removed from the drilled hole prior to tapping.
8. Using compressed air, clean out any chips.
Fig 6: Tapping Threads Using Tapping Wrench - Inboard Bolt Holes
Courtesy of GENERAL MOTORS CORP.
IMPORTANT:
• 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.
9. Using a suitable tapping wrench, tap the threads of the drilled hole by hand only.
Fig 7: View Of Tap Upper & Lower Marks, Fixture Plate & Bushing
Courtesy of GENERAL MOTORS CORP.
10. In order to tap the new threads for the insert to the proper depth, rotate the tap into the cylinder head bolt hole until the first mark (1) on the tap aligns with the top of the drill bushing (3).
Fig 8: View Of Fixture Plate & Components - Inboard Bolt Holes
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Remove the fixture plate prior to installing the insert with the installer tool.
11. Remove the fixture plate bolts (2).
12. Remove the fixture plate (3) and bushing (1).
Fig 9: Cleaning Out Metal Chips
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: All chips must be removed from the tapped hole prior to insert installation.
13. Using compressed air, clean out any chips.
Fig 10: Spraying Cleaner Into Tapped Hole
Courtesy of GENERAL MOTORS CORP.
14. Spray cleaner GM P/N 12346139, GM P/N 12377981 (Canadian P/N 10953463) or equivalent into the tapped hole.
Fig 11: Cleaning Out Metal Chips
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: All chips must be removed from the tapped hole prior to insert installation.
15. Using compressed air, clean out any chips.
Fig 12: Lubricating Installer Tool Using Driver Oil
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Do not allow oil or other foreign material to contact the OD of the insert.
16. Lubricate the threads of the driver installation tool (2) with the driver oil J 42385-110 (1).
Fig 13: View of Bushing Type Insert
Courtesy of GENERAL MOTORS CORP.
17. Install the insert (2) onto the driver installation tool (1).
Fig 14: Applying Threadlock To Insert
Courtesy of GENERAL MOTORS CORP.
18. Apply threadlock sealant GM P/N 12345493, (Canadian P/N 10953488), J 42385-109, LOCTITE 277®, or equivalent (1) to the insert OD threads (2).
Fig 15: Installing Insert & Installation Driver - Inboard Bolt Holes
Courtesy of GENERAL MOTORS CORP.
19. Install the insert and installation driver (1) into the tapped hole by hand only.
20. Start the insert into the threaded hole.
IMPORTANT: 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.
21. Install the insert until the flange of the insert contacts the counterbored surface.
IMPORTANT: 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.
22. Continue to rotate the driver installation tool through the insert.
23. Inspect the insert for proper installation into the tapped hole.