Once the
Crankshaft and connecting rods have been cleaned and inspected, and a decision has been made regarding bearing replacement, the connecting rods can be reinstalled on the crankshaft. If new bearings are being used, check the oil clearances before the final installation of the connecting rods. If the clearances are within the specified limits, proceed with the installation. Never assume that the clearances are correct, even if new bearings are involved. Make sure the bearing faces and backs are perfectly clean, then fit them to the connecting rod and cap. The tab on each bearing must be engaged in the recess in the cap or connecting rod. Clean the number one connecting rod journal on the crankshaft, then slip the number one connecting rod into place. Ensure that the mark on the side of the connecting rod is facing the front of the crankshaft. Apply a length of Plastigage to the crankshaft journal, just off-center. Gently install the connecting rod cap in place, without turning the connecting rod on the journal. Make sure the mating mark on the cap is on the same side as the mark on the connecting rod. Lubricate the threads of the connecting rod nuts or bolts and tighten them. Remove the connecting rod nuts or bolts without allowing the connecting rod to turn on the journal, then remove the cap. Examine the Plastigage and compare its width to the scale on the Plastigage package. The connecting rod oil clearance is usually about 0.001 to 0.002 inches. Consult an automotive machine shop for the clearance specified for the rod bearings on your engine. If the clearance is within specifications, proceed with checking the other three connecting rods. If the connecting rod clearances are all within specifications, lubricate both halves of the bearings of connecting rod number 1 with moly-based assembly lube and install the connecting rod nuts or bolts. Tighten them, working up to it in three steps. Repeat the procedure for the remaining connecting rods. Do not mix up the connecting rods and caps, and do not install the connecting rods backwards. After the connecting rods have been installed, rotate them by hand and check for any obvious binding. As a final step, recheck the connecting rod side clearance.