Connecting rod bearing
Checking the working clearance
1. Clean the back of the bushing and its mounting location in the connecting rod and the connecting rod cap.
2. Install the earbuds in place.
3. One method is to install the connecting rod bearing caps, along with the bushing, on the connecting rods and tighten them to the correct torque. Measure the inside diameter of each assembled pair of bearing shells. Measure the diameter of each connecting rod journal of the crankshaft. Subtract the corresponding diameter of the crankshaft journal from the measured bearing diameter.
4. The second and more accurate method is to use a product known as Plastigage. This is a round plastic rod that is compressed between the bushing and the crankshaft journal. After removing the connecting rod bearing cap, the deformed plastic rod is measured with a special gauge that is included with Plastigage. The procedure for using Plastigage is as follows. Install without lubrication the connecting rods on the crankshaft, the crankshaft journals and liners must be completely clean and dry. Cut off a few pieces of plastic rod and install them on each crankshaft journal. Install the covers with the bottom liners and tighten the mounting bolts to the required torque.
5. Do not rotate the engine crankshaft while measuring the clearance using the Plastigage method. Unscrew the cover of the insert attachment, remove it and attach the scale ruler printed on the package to the deformed plastic rod. By comparing the width of the deformed plastic rod with the reference width on the scale bar, determine the amount of gap. Finally, carefully clean any traces of Plastigage from the liners and crankshaft.
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