Usage of Cylinder Head Gaskets{1124} Caterpillar

Engine: 3114 3116 3126 3126B

Introduction

Cylinder head gaskets for 3114, 3116, and 3126 engines are available in two thicknesses. There is a "Standard" cylinder head gasket and a "Thick" cylinder head gasket for each of these engines. The 3126B engine has a different cylinder head with three valves per cylinder.

Note: Contact your Caterpillar Dealer for more information.

The correct gasket to use during a repair or a rebuild of the engine depends on the height of the top surface of the cylinder block. Use the following information and illustrations in order to determine the correct cylinder head gasket. The use of an incorrect cylinder head gasket will affect performance of the engine.

Note: Cylinder blocks must not be machined to a "Dimension A" that is less than 321.50 mm (12.6673 inch). Refer to Illustration 1.

1. "Standard" cylinder head gaskets have a 1.5 mm (0.060 inch) assembled thickness. Use a "Standard" cylinder head gasket with a cylinder block that meets one of the following conditions:
   • The top surface of the cylinder block has never been machined or resurfaced for repair.

   • The top surface of the cylinder block has been previously machined for repair, but the cylinder block meets the "Dimension A" guidelines for a "Standard" cylinder head gasket.

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NOTICE
Failure to use a cylinder head gasket of the correct thickness may cause engine damage.

2. The "Thick" cylinder head gaskets have a 1.75 mm (0.070 inch) assembled thickness. Use a "Thick" cylinder head gasket with a cylinder block that meets the following conditions:
   • The top surface of the cylinder block has been machined or resurfaced for repair. "Dimension A" for the height of the cylinder block meets the guidelines for a "Thick" cylinder head gasket.

   • "TG" is stamped on the surface of the cylinder block. Refer to Illustration 2. The "TG" stamp would indicate that the cylinder block has been previously machined to "Dimension A", which would require a "Thick" cylinder head gasket.

Note: For a remanufactured cylinder block, the "TG" will also be stamped on the Remanufacture Information Plate. The Remanufacture Information Plate is located on the rear of the cylinder block. Refer to Illustration 3.

The Top Of The Cylinder Block Has Been Machined As Part Of Your Repair Process

The height of the cylinder block must be measured if the top surface of the cylinder block has been machined as part of your repair process. The height of the cylinder block will determine the cylinder head gasket that must be used.

Measure The Height Of The Cylinder Block

Measuring the height of the cylinder block is one method of determining the correct cylinder head gasket.

Illustration 1	g00613631
Dimension (A) is from the top of the cylinder block to the centerline of the crankshaft. Dimension (A) can be measured from the top surface of the cylinder block to the machined surface that mates with the main bearing cap.

Measure the height of the cylinder block "Dimension A". Use Table 1 and determine if the "Standard" cylinder head gasket or the "Thick" cylinder head gasket is required. Refer to Table 2 in order to determine the correct part number of the cylinder head gasket for your application.

Note: After machining, if the "Thick" cylinder head gasket is required, then permanently stamp the letters "TG" in the proper location for future identification and future servicing. Refer to the ""Identify a "TG" Stamp" " section of this publication.

The Top Of The Cylinder Block Has Not Been Machined As Part Of Your Repair Process

If you did not machine the top of the cylinder block, then determine whether the cylinder block has been previously machined.

• "TG" is stamped on the surface of the cylinder block and/or on the "Remanufacture Information" plate. Refer to Illustration 2 and Illustration 3. Use the "Thick" cylinder head gasket if you find a "TG" stamp.

• Use a "Standard" cylinder head gasket if the top surface of the cylinder block has never been machined and there is not a "TG" stamp.

• If the original cylinder head gasket is available for inspection, ensure that the original cylinder head gasket was the correct gasket. Refer to Table 2 in order to determine the part number for the new cylinder head gasket. "Standard" cylinder head gaskets do not have the sawtooth pattern. Refer to Illustration 4. "Thick" cylinder head gaskets have the sawtooth pattern. Refer to Illustration 5.

• If you are not sure that the original cylinder head gasket was the correct gasket, then measure the height of the cylinder block. Refer to ""Measure The Height Of The Cylinder Block" ".

Identify a "TG" Stamp

"TG" will be stamped on the top surface of a remanufactured cylinder block that has been machined by Caterpillar to a dimension between 321.50 to 321.75 mm (12.6575 to 12.6673 inch). A Caterpillar Remanufactured Cylinder Block that requires the "Thick" cylinder head gasket will also have "TG" on the Remanufacture Information Plate. The Remanufacture Information Plate is located on the rear face of the cylinder block. Refer to Illustration 3.

Illustration 2	g00619401
"TG" stamp on top surface of cylinder block

Illustration 3	g00619437
(1) Location of remanufacture information tag

If you can identify a "TG" stamping, then use the "Thick" cylinder head gasket. If there is not a "TG" stamping and the top surface of the cylinder block has never been machined for repair, the "Standard" cylinder head gasket must be used.

Determine The Part Number of the Original Cylinder Head Gasket

If the original cylinder head gasket is available for inspection, ensure that the original cylinder head gasket was the correct gasket. Refer to Table 2 in order to determine the part number for the new cylinder head gasket. If you are not sure that the original cylinder head gasket was the correct gasket, then measure the height of the cylinder block. Refer to the ""Measure The Height Of The Cylinder Block" " section of this publication.

• Read the part number directly from the original cylinder head gasket.

• Determine the part number from the physical characteristics of the original cylinder head gasket.

Illustration 4	g00617977
Illustration of a "Standard" cylinder head gasket

Use the "Standard" cylinder head gasket when the original cylinder head gasket has the following characteristics:

• The part number (3) on the original cylinder head gasket is one of the part numbers that are listed under "Part Number for Standard Cylinder Head Gasket" in Table 2.

• The original cylinder head gasket does not have a sawtooth pattern on the edge of the cylinder head gasket (2) .

Illustration 5	g00617897
Illustration of a "Thick" cylinder head gasket

The "Thick" cylinder head gasket must be used if the original cylinder head gasket has the following characteristics:

• The part number (3) on the original cylinder head gasket is one of the part numbers that are listed under "Part Number for Thick Cylinder Head Gasket" in Table 2.

• The original cylinder head gasket has a sawtooth pattern (2) that is near tappet chamber (4) and between cylinder number 1 and cylinder number 2.