Cylinder Head Bolt Hole Thread Repair

WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

The cylinder head bolt hole required tools consist of the following:

Drill (1) J 42385-402
Tap (2) J 42385-403
Installation driver (3) J 42385-404
Alignment pin (4) J 42385-303
Bushing (5) J 42385-302
Bolts (6) J 42385-421
Fixture plate (7) J 42385-401

CAUTION: Refer to SAFETY GLASSES CAUTION in Cautions and Notices.

Fig 1: Identifying Tools Required For Cylinder Head Bolt Hole Thread Repair

Courtesy of GENERAL MOTORS CORP.

IMPORTANT:

Remove the fixture plate prior to installing the insert with the installer tool.
The use of a cutting type fluid GM P/N United States 1052864, GM P/N Canada 992881, WD 40® or equivalent is recommended when performing the drilling, counterboring and tapping procedures.

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

Position the fixture plate (3) with the bushing (1) installed over the cylinder head bolt hole to be repaired (4).
Loosely install the fixture plate bolts (2) into the remaining cylinder head bolt holes.

Fig 2: Positioning Fixture Plate With Bushing Installed Over Cylinder Head Bolt Hole
Courtesy of GENERAL MOTORS CORP.
Position the alignment pin (1) through the bushing and into the cylinder head bolt hole.
With the alignment pin in the desired cylinder head bolt hole, tighten the fixture retaining bolts (2).
Remove the alignment pin (1) from the cylinder head bolt hole.

Fig 3: Positioning Alignment Pin Through Bushing And Into Cylinder Head Bolt Hole
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 out the threads of the damaged hole.

Fig 4: Drilling Out Threads Of Damaged Hole
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IMPORTANT: All chips must be removed from the drilled hole prior to tapping.
Using compressed air, clean out any chips.

Fig 5: Cleaning Out Chips From Hole By Using Compressed Air
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.
Using a suitable tapping wrench, tap the threads of the drilled hole.

Fig 6: Tapping Threads Of Drilled Hole
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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 7: Aligning First Mark On Tap With Top Of Drill Bushing
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IMPORTANT: Remove the fixture plate prior to installing the insert with the installer tool.
Remove the fixture plate bolts (2).
Remove the fixture plate (3) and bushing (1).

Fig 8: Removing Fixture Plate And Bushing
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IMPORTANT: All chips must be removed from the tapped hole prior to insert installation.
Using compressed air, clean out any chips.

Fig 9: Cleaning Out Chips From Hole By Using Compressed Air
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Spray cleaner GM P/N United States 12377981, GM P/N Canada 10953463 or equivalent into the tapped hole.

Fig 10: Spraying Cleaner Into Tapped Hole
Courtesy of GENERAL MOTORS CORP.

IMPORTANT: All chips must be removed from the tapped hole prior to insert installation.
Using compressed air, clean out any chips.

Fig 11: Cleaning Out Chips From Hole By Using Compressed Air
Courtesy of GENERAL MOTORS CORP.

IMPORTANT: 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 driver oil (1) J 42385-110.

Fig 12: Lubricating Threads Of Driver Installation Tool With Driver Oil
Courtesy of GENERAL MOTORS CORP.
Install the insert (2) onto the driver installation tool (1).

Fig 13: Installing Insert Onto Driver Installation Tool
Courtesy of GENERAL MOTORS CORP.
Apply threadlock sealant GM P/N United States 12345493, GM P/N Canada 10953488, J 42385-109, LOCTITE 277®, or equivalent (1) to the insert OD threads (2).

Fig 14: Applying Threadlock Sealant To Insert OD Threads
Courtesy of GENERAL MOTORS CORP.
Install the insert and installation driver (1) into the tapped hole.
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.
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.
Continue to rotate the driver installation tool through the insert.
Inspect the insert for proper installation into the tapped hole.

Fig 15: Installing Insert And Installation Driver Into Tapped Hole
Courtesy of GENERAL MOTORS CORP.