GASKET-CYLINDER HEAD 3706891 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
On some 3500 Engines, the outer valve spring is failing from fatigue due to inclusions in the base material. The 281-6157 Valve Spring can be identified by the white stripe of paint on the outer diameter of the spring. The spring's coil is wound in a counterclockwise direction.Solution
New valve components are available. The new valve components exhibit improvements in durability. Use the new valve components in engine overhauls. These new part numbers are in limited supply. Limit orders for parts to quantities that are needed for specific engine rebuilds.
Table 1
Identification of the Valve Springs    
Former Spring and Identification     New Spring and Identification    
281-6157
Outer spring     White stripe
CCW coil (1)     316-5976
Outer spring     Yellow stripe
CW coil (2)    
194-4902
Inner spring     Orange stripe
CW coil (2)     316-5977
Inner spring     Yellow stripe
CCW coil (1)    
( 1 ) Counterclockwise
( 2 ) ClockwiseIn addition to the springs, the other new valve components are listed in Table 2.
Table 2
Former Part     New Part    
197-7062 Rotocoil As (intake)     316-5978 Rotocoil As (intake)    
197-7063 Rotocoil As (exhaust)     316-5979 Rotocoil As (exhaust)    
197-7006 Valve Stem Seal (intake)     316-5980 Valve Stem Seal (intake)    
209-0962 Washer (exhaust)     316-5981 Washer (exhaust)    The 317-2440 Cylinder Head Gp has been released with the above listed components.The 317-2440 Cylinder Head Gp has replaced the 201-4257 Cylinder Head Gp for the affected serial numbers.The 201-4257 Cylinder Head Gp can be converted to the 317-2440 Cylinder Head Gp by exchanging the above listed components.Note: These new parts must be used in conjunction with each other. The new parts and the former parts must not be mixed.Serial number effectivity is listed in Table 3.
Table 3
Serial Number Effectivity    
Model     Serial Number    
793D     S/N:FDB00710-00712    
793D     S/N:FDB00729-UP    
797B     S/N:JSM00326-00326    
797B     S/N:JSM00328-00328    
797B     S/N:JSM00330-UP    
994F     S/N:44200250-UP    
3516B     S/N:8WM01693-UP