Technical Service: 2001-2005 Duramax Head Gasket Markings

  • Reference Number(s): 07-06-01-009A, Date of Issue:  November 02, 2009
  • Affected Model(s): 2001-2005 Chevrolet Silverado; 2003-2005 Chevrolet Kodiak C4500/5500 Series; 2001-2005 GMC Sierra; 2003-2005 GMC TopKick C4500/5500 Series; with 6.6L Duramax® Diesel Engine (VINs D, 1, 2 – RPOs LB7, LLY)Supercedes:This bulletin is being revised to remove the Warranty Information and update the Parts Information. Please discard Corporate Bulletin Number 07-06-01-009 (Section 06 – Engine/Engine Mechanical).

6.6L LB7, LLY DURAMAX® DIESEL ENGINE CYLINDER HEAD GASKET MISSING THICKNESS GRADE MARKINGS – INSPECT BLOCK FOR STAMPINGS

SERVICE INFORMATION

A small number of remanufactured engines were built using oversized bore or milled deck gaskets that do not have any thickness grade identification markings. These engines may show up in any model year from 2001-2005 if the vehicle has received an engine replacement.

Fig 1: Block Stampings Indicating Cylinder Overbore & Milled Deck — GM1775614
Courtesy of GENERAL MOTORS CORP.

Inspect the block for stampings (1) indicating cylinder overbore and a milled deck. The overbore gasket accommodates all cylinder bores from 0.010-0.030″. All blocks that are milled are also over-bored.

Stamped ID Cylinder Bore Size (in) Top Deck (STD or Milled)
0S 0.010 STD
0S 0.020 STD
0S 0.030 STD
01M 0.010 Milled
02M 0.020 Milled
0M 0.030 Milled
Crimped Construction Style Head Gasket
Fig 2: First Generation Head Gasket (Crimped Construction) — GM1743166
Courtesy of GENERAL MOTORS CORP.

First generation head gasket crimped construction (1).

Riveted Construction Style Head Gasket
Fig 3: Second Generation Head Gasket (Riveted Construction) — GM1743169
Courtesy of GENERAL MOTORS CORP.

Second generation head gasket riveted construction (1).

IMPORTANT: The gaskets with no thickness grade specifications will be of crimped construction as opposed to riveted construction. These gaskets require a higher torque specification than what is published in SI. Use the following torque specification when servicing an engine using a head gasket of crimped construction.

Cylinder Head Bolt Torque Specification For Crimped Construction Head Gasket

Refer to Cylinder Head Replacement in SI. Tighten the cylinder head bolts in the following steps using the sequence below:

Tighten:

  1. Tighten the M12 bolts a first pass to 50 N.m (37 lb ft).
  2. Tighten the M12 bolts a second pass to 80 N.m (59 lb ft).
  3. Tighten the M12 bolts a third pass to 90 degrees, using Torque Angle Meter J 45059.
  4. Tighten the M12 bolts a final pass to 75 degrees, using Torque Angle Meter J 45059.
  5. Tighten the M8 bolts to 25 N.m (18 lb ft).
Crimped Cylinder Head Gasket Parts Information
Part Number Description Qty
98040128 Gasket, Cyl Hd, (Oversize Bore) – RH 1
97358465 Gasket, Cyl Hd, (Oversize Bore and Milled Deck) – RH 1
98040130 Gasket, Cyl Hd, (Oversize Bore) – LH 1
97358466 Gasket, Cyl Hd, (Oversize Bore and Milled Deck) – LH 1
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