ROD ASSEM. 7J9721 - Caterpillar

3500 Family Of EnginesDescription of Change: New cylinder block groups are being used. The new cylinder blocks contain additional material in the camshaft bore area. As a result of this additional material, the air plenum drain holes, between number 1 and number 3 cylinder on the right hand side and the rear two cylinders on the left hand side, have been eliminated. In addition, two bolt holes, no longer being used, were deleted from the left hand front and right hand rear of the block.
Typical Right Hand Cylinder Head Face. Location of the air plenum drain hole (1) to be removed. Location of two tapped holes (2) to be removed.
Typical Left Hand Cylinder Head Face. Location of the air plenum drain hole (3) to be removed. Location of two tapped holes (4) to be removed.Adaptable To: See the chart for the new and former cylinder block group part numbers. The former cylinder block groups are canceled. The new cylinder block groups are adaptable to first production. If needed, for an early engine requiring the bolt holes that were eliminated, use a 1U8162 Drill Bit [8.20 mm (.323 in) diameter] and the original adapters as drill guides. Drill four holes 25.0 mm (.98 in) deep. Tap the four holes with 3/8-16 thread, 17.0 mm (.67 in) deep.