TUBE AS 8Y8675 - Caterpillar

1100, 3100 And 3200 Series EnginesDescription of Change: A new cylinder head gasket is available for all 1100, 3100 and 3200 Series Engines. The new gasket has a higher fire ring projection (difference between the thickness of the fire ring and the gasket body). Material has been added to the fire ring wrapper between cylinders. This requires a locating hole in the gasket. Also, each head bolt now requires a light coat of 6V4876 Molykote Lubricant, instead of engine oil, on the bolt threads and washer. The head bolt tightening procedure has also been changed (see Cylinder Head Bolt Torque Information). These changes will provide an improved combustion seal.Adaptable As: The new 7W2059 Cylinder Head Gasket is a direct replacement for all former cylinder head gaskets in all applications for these engines. The new gasket is in effect as shown in Chart A. Special Instruction, Form SEHS8612-O1 is included with each gasket and provides installation instructions. Different cylinder head bolt torque must be used on earlier and later engines. See Cylinder Head Bolt Torque Information. Cylinder Head Bolt Torque Information
All 1100, 3100 and earlier 3200 Series Engines used cylinder head bolts with a torque specification of 130 N m (95 lb ft).
These earlier head bolts can be identified by six dash marks on the bolt head. See Illustration 1.
Later 3204 and 3208 Engines use stronger cylinder head bolts with a higher torque specification. These bolts can be identified by seven dash marks on the bolt head. See Illustration 1.
The higher cylinder head bolt torque may be used on earlier engines ONLY if the bolts are replaced with the later higher strength bolts (seven dash marks on the bolt head). If the earlier bolts are tightened to the later torque specification, they may yield (stretch) and lose their clamping force.
Illustration 1. Bolt head identification.
Illustration 2. Cylinder head bolt tightening sequence.Before installing the cylinder head bolts, put a light coat of 6V4876 Molykote Lubricant on the bolt threads and washer surfaces. Tighten the bolts as shown in the Head Bolt Chart and Illustration 2.