Connecting Rod Bearing Replacement

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.

3. Clean the crankshaft 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, and tighten the bolts.
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 upper half of the bearing, install a new, complete bearing with the same color code, 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 clearance again. If the proper clearance cannot be obtained by using the appropriate larger or smaller bearings, replace the crankshaft Crankshaft and Piston Removal and start over.

Connecting Rod Bearing Selection

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

Connecting Rod Big End Bore Code Locations

2. Each connecting rod falls into one of four tolerance ranges (from 0 to 0.024 mm (0.0009 in.), in 0.006 mm (0.0002 in.) increments) depending on the size of its big end bore.
It's then stamped with a number or bar (1, 2, 3, or 4) indicating the range. You may find any combination of 1, 2, 3, or 4 in any engine.

If the codes are indecipherable because of an accumulation of dirt and dust, do not scrub them with a wire brush or scraper. Clean them only with solvent or detergent.

Normal Bore Size: 43.0 mm (1.69 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.