ENGINE AR-COMPLETE 3437696 - Caterpillar

Engines Remanufactured By Cat ( 62W)At an earlier time, a change was made to use higher strength bolts and increase bolt torque for the cylinder heads on new 3208 Engines. The change was not made to 3208 Engines Remanufactured by Cat at that time, because most of these units had the earlier bolts. The change has now been made to these engines, and the later bolts are installed in all engines with Serial Numbers 62W14950-Up.
With the use of the later cylinder head bolts, the final (last) torque is increased to 150 7 N m (110 5 lb ft). The final torque used for the earlier bolts is 130 7 N m (95 5 lb ft). Do not tighten earlier bolts to the higher torque value.
Identification of the bolts can be made by the number of marks on the bolt heads. Earlier bolts have six marks, and later bolts have seven marks. An Illustration of these marks is shown in the Specifications section of the Service Manual for 3208 Diesel Truck Engines 40S1-Up. This Service Manual also shows the correct sequence and necessary steps to tighten all the head bolts, with the initial (first) torque and final (last) torque for both earlier and later bolts.