Connecting Rod Bearing Replacement

Connecting Rod Bearing Replacement

Connecting Rod Bearing Clearance Inspection

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

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

3. Place one strip of plastigage across the connecting rod journal.

4. Reinstall the bearing half and the connecting rod cap, then torque the connecting rod bolts.

NOTE:

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





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










6. 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.

7. 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

Each connecting rod falls into one of four tolerance ranges (from 0 to 0.024 mm (0.00094 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 or bar (1, 2, 3, or 4/I, II, III, or IIII) indicating the range. You may find any combination of 1, 2, 3, or 4/I, II, III, or IIII in any engine.

Big End Bore Size: 60.0 mm (2.362 in)

Inspect the connecting rod for cracks and heat damage.

Big End Bore Code Locations

Numbers or bars have been stamped on the side of each connecting rod as a code for the size of the big end. Use them, and the letters or bars stamped on the crank (codes for rod journal size), to choose the correct bearings. 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.










Connecting Rod Journal Code Locations (Letters or Bars)