Cylinder Head Bolt Hole Thread Repair

CAUTION: Refer to Safety Glasses Caution .

IMPORTANT:

The use of a cutting type fluid GM P/N 1052864 (Canadian P/N 992881), WD 40®, or equivalent, is recommended when performing the drilling and tapping procedures.
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.

Fig 2: View Of Fixture Plate, Bolts, Bushing & Cylinder Hole

Courtesy of GENERAL MOTORS CORP.

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).
Position the alignment pin (1) through the bushing and into the hole.

Fig 3: View Of Alignment Pin & Fixture Retaining Bolts
Courtesy of GENERAL MOTORS CORP.
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).

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

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

Fig 5: Drilling Cylinder Head Bolt Hole

Courtesy of GENERAL MOTORS CORP.

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.
Using compressed air, clean out any chips.
Using a tap wrench, tap the threads of the drilled hole.

Fig 6: Tapping Threads Of Drilled Hole Using Tapping Wrench
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In order to tap the new threads to the proper depth, rotate the tap into the hole until the mark (1) on the tap aligns with the top of the drill bushing (3).

Fig 7: View Of Tap Upper & Lower Marks, Fixture Plate & Bushing
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Remove the fixture plate (2), bushing (3), and bolts.
Using compressed air, clean out any chips.
Spray cleaner GM P/N 12346139, GM P/N 12377981 (Canadian P/N 10953463), or equivalent, into the hole.
Using compressed air, clean any cutting oil and chips out of the hole.

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

Fig 8: Lubricating Installer Tool Using Driver Oil

Courtesy of GENERAL MOTORS CORP.

Lubricate the threads of the installer tool (2) with the driver oil (1).
Install the insert (2) onto the driver tool (1).

Fig 9: Installing Insert Onto Driver Tool
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Apply threadlock LOCTITE™ 277, J 42385-109 (1), or equivalent, to the insert OD threads (2).

Fig 10: Applying Threadlock To Insert
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Install the insert and driver (1) into the hole.

Fig 11: Installing Insert & Driver Into Cylinder Bolt Hole
Courtesy of GENERAL MOTORS CORP.

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.