Cylinder Head Bolt Hole Thread Repair

WARNING: This page is about a different variant/trim than selected.

The cylinder head bolt hole thread repair kit consists of the following items:

Fig 1: Identifying Thread Repair Kit Components
Courtesy of GENERAL MOTORS COMPANY

NOTE: The tools listed may not necessarily represent the exact tools used for the procedure.
- Drill (1)
- Tap (2)
- Installer (3)
- Sleeve (4)
- Alignment Pin (5)
- Bushing (6)
- Bolts (7)
- Fixture Plate (8)
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).

Fig 2: Identifying Fixture Plate. Bolts, & Bushing
Courtesy of GENERAL MOTORS COMPANY

WARNING: Refer to Safety Glasses and Compressed Air Warning .

NOTE:
The use of a cutting fluid, WD 40® or equivalent, is recommended when performing the drilling and tapping procedures. Refer to Adhesives, Fluids, Lubricants and Sealers .

Driver oil MUST be used on the installer driver tool.

The tool kits are designed for use with either a suitable tap wrench or drill motor.
Position the alignment pin (1) through the bushing and into the hole.

Fig 3: Identifying Alignment Pin
Courtesy of GENERAL MOTORS COMPANY
With the alignment pin in the desired hole, tighten the fixture retaining bolts (2).
Remove the alignment pin from the hole.
Install the sleeve (2) onto the drill (1), if required.

Fig 4: View Of Stop Collar & Counterbore Drill
Courtesy of GENERAL MOTORS COMPANY
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.

Fig 5: Drilling Out Threads Of Damaged Hole
Courtesy of GENERAL MOTORS COMPANY

NOTE: During the reaming process, it is necessary to repeatedly remove the drill and clean the chips from the hole.
Using compressed air, clean out any chips.
WARNING: Refer to Safety Glasses and Compressed Air Warning .
Using a tap wrench, tap the threads of the drilled hole.

Fig 6: Tapping Threads Of Drilled Hole With Tap Wrench
Courtesy of GENERAL MOTORS COMPANY
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 (3) on the tap align with the top of the drill bushing (2).

Fig 7: View Of Fixture Plate, Drill Bushing & Tool Marking
Courtesy of GENERAL MOTORS COMPANY
Remove the fixture plate (1), bushing (2) and bolts.
Using compressed air, clean out any chips.
WARNING: Refer to Safety Glasses and Compressed Air Warning .

WARNING: Refer to Cleaning Solvent Warning .
Spray cleaner into the hole. Refer to Adhesives, Fluids, Lubricants and Sealers .
Using compressed air, clean any cutting oil and chips out of the hole.
Lubricate the threads of the installer tool (2) with the driver oil (1).

Fig 8: Lubricating Installer Tool Using Driver Oil
Courtesy of GENERAL MOTORS COMPANY

NOTE: Do not allow oil or other foreign material to contact the outside diameter (OD) of the insert.
Install the insert (2) onto the driver tool (1).

Fig 9: View of Bushing Type Insert
Courtesy of GENERAL MOTORS COMPANY
Apply threadlock LOCTITE™ 277, EN 42385 - 109 loctite (1) or equivalent to the insert OD threads (2).

Fig 10: Applying Threadlock To Insert
Courtesy of GENERAL MOTORS COMPANY
Install the insert and driver (1) into the hole.

Fig 11: Installing & Inserting Driver Into Hole
Courtesy of GENERAL MOTORS COMPANY

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.