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6.6L LB7, LLY Duramax Diesel Engine Cylinder Head Gasket Missing Thickness Grade Markings - Inspect Block for Stampings

Subject: 6.6L LB7, LLY Duramax® Diesel Engine Cylinder Head Gasket Missing Thickness Grade Markings - Inspect Block for Stampings

Models: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)



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.


Object Number: 1775614  Size: SH

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


Object Number: 1743166  Size: SF

First generation head gasket crimped construction (1).

Riveted Construction Style Head Gasket


Object Number: 1743169  Size: SF

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

97358467

Gasket, Cyl Hd, (Oversize Bore) - RH

1

97358465

Gasket, Cyl Hd, (Oversize Bore and Milled Deck) - RH

1

97358468

Gasket, Cyl Hd, (Oversize Bore) - LH

1

97358466

Gasket, Cyl Hd, (Oversize Bore and Milled Deck) - LH

1

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time

J0500

Gasket, Cylinder Head - Right Bank - Replace

Use Published Labor Operation Time

J0501

Gasket, Cylinder Head - Left Bank - Replace

J0507

Gasket, Cylinder Head - Both Banks - Replace