Connecting Rod Bearing: Service and Repair

Connecting Rod Bearing Replacement

Connecting Rod Bearing Clearance Inspection

1. To check rod bearing-to-journal oil clearance, remove the bearing cap Crankshaft and Piston Removal.

2. Remove the connecting rod cap and the bearing half Crankshaft and Piston Removal.

3. Clean the connecting rod journal and the bearing half with a clean shop towel.

4. Place plastigage across the rod journal.

5. Reinstall the bearing half and connecting rod cap, then torque the bolts to 10 N-m (1.0 kgf-m, 7.4 lbf-ft) +90°.

NOTE:

- Apply new engine oil to the bolt threads and flanges.
- Do not rotate the crankshaft during inspection.

6. Remove the connecting rod cap and the bearing half and measure the widest part of the plastigage.










7. If the plastigage measures too wide or too narrow, remove the connecting rod cap and the upper half of the bearing. Install a new, complete bearing with the same color code(s), and recheck the clearance. Do not file, shim, or scrape the bearings or the caps to adjust clearance.

8. If the plastigage shows the clearance is still incorrect, try the next larger or smaller bearing (the color listed above or below that one), and check the clearance again. If the proper clearance cannot be obtained by using the appropriate larger or smaller bearings, replace the crankshaft, and start over Crankshaft and Piston Removal.

Connecting Rod Bearing Selection

1. Inspect the connecting rod for cracks and heat damage.

Big End Bore Code Locations

2. Each connecting rod has a tolerance ranges from 0 to 0.024 mm (0.00095 in), in 0.006 mm (0.00024 in) increments, depending on the size of its big end bore.
It is then stamped with a number (1, 2, 3, or 4) indicating the range. You may find any combination of numbers in any engine.
(Half the number is stamped on the connecting rod, the other half is on the rod cap.) If you cannot read the code because of an accumulation of oil and varnish, do not scrub it with a wire brush or scraper. Clean it only with solvent or detergent.

Big End Bore Size: 43.0 mm (1.693 in)






Connecting Rod Journal Code Location

3. The connecting rod journal codes are stamped on the crankshaft in either locations.










4. Use the big end bore codes and the rod journal codes to select appropriate replacement bearings from the following table.

NOTE:

- Color code is on the edge of the bearing.
- When using bearing halves of different colors, it does not matter which color is used in the top or bottom.