Before going into the process of changing rod bearing and installing new ones, there are certain basic precautions that one needs to take care. Temperature variations result in inaccurate measurements and eventually improper bearing installation. Hence, the entire process should be completed inside a temperature-controlled zone. It is always necessary to calibrate all the required instruments prior to starting the process so that they provide consistent and accurate measurements. Successful bearing installation is ensured only if a high-quality lubricant is used.
In addition to all these processes, availability of bearing manual is useful during the process. The first step of changing rod bearing is main-bearing clearance check. The edges of the main caps and journals should be properly cut and polished so as to permit accurate fitting of the bearings. Accuracy of the bearing tang depth is monitored by placing the bearing and pressing it past the block mating surface. If the bearing goes in conveniently, the tang depth is proper. Apart from the tang depth, the bearings should also be checked for correct end-to-end length. Both the tang depth and bearing length procedures are carried out on the main and rod bearings.
After checking the bearings, the oiling system passages should be inspected so as to avoid any flow restrictions that could be caused due to bearing overlap. Sometimes, it is advisable to drill 0.060- to 0.090-inch holes on both ends of the bearings so as to promote better oil flow and decrease the effects caused due to temperature increase on the bearings. Once this is done, the bearings are then verified so that they have a correct clearance to the crankshaft.
Once all the preliminary processes are done, the bearings are now seated into their place and the main cap is rotated down. A mallet could be used to ensure proper seating of the main cap. The final step of the process is to determine the eccentricity. This is done by measuring inside the main bore vertically and diagonally.
Once you are done, you have managed to successfully change the rod bearing on your 1996 Toyota Corolla.