Cylinder Head Bolt Hole Thread Repair

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

Tools Required

J 42385-2030 M11 x 2.0 See Special Tools Cylinder Head Bolt - Northstar/Premium V8 Thread Insert Kit

Fig 1: Identifying Thread Repair Kit Components

Courtesy of GENERAL MOTORS CORP.

The cylinder head bolt hole thread repair kit J 42385-2030 components consist of the following. See Special Tools .

Drill (1) J 42385-2031
Tap (2) J 42385-2032
Installation driver (3) J 42385-2033
Stop collar (4) for inboard holes J 42385-2034
Alignment pin (5) J 42385-303
Bushing (6) J 42385-302
Bolts (7) J 42385-2035 and J 42385-2036
Fixture plate (8) J 42385-301

NOTE: Ensure the cylinder head bolts, tools and inserts that are being used are the proper pitch or engine damage will occur. The thread pitch on the M11 cylinder head bolts and the engine block cylinder head bolt holes have been revised. In order to install the proper pitch insert it is important to identify which thread pitch is being used. Cylinder head bolts with a pitch of 1.5 mm have a thread length of about 48 mm (1.890 in) long. Cylinder head bolts with a pitch of 2.0 mm have a thread length of about 67 mm (2.638 in) long.

IMPORTANT:

Cylinder head bolt holes with a pitch of 2.0 mm (0.08 in) use the tooling from the J 42385-2030 . See Special Tools . Cylinder head bolt holes with a pitch of 1.5 mm (5.90 in) use the tooling from the J 42385-2000 .
Verify the depth of the cylinder head bolt hole and the pitch of the cylinder head bolt threads. Measure the depth from the deck surface of the block to the bottom of the cylinder head hole. All cylinder head holes should use only one of the bushings. Never use both bushings to repair a block.

With M11 bolts with a 1.5 mm pitch:

Use the bushing J 42385-2022 for inboard holes that measure 73 mm (2.874 in) deep and outboard holes that measure 89.5 mm (3.524 in) deep.
Use the bushing J 42385-302 for inboard holes that measure 80 mm (3.150 in) deep and outboard holes that measure 96.5 mm (3.799 in) deep.

With M11 bolts with 2.0 mm pitch:

Use the bushing J 42385-302 for inboard holes that measure 73 mm (2.874 in) deep and outboard holes that measure 89.5 mm (3.524 in) deep.