Connecting Rod Bearing: Testing and Inspection

OIL CLEARANCE






1. Check the matchmarks on the connecting rod and cap to ensure correct reassembly.
2. Remove the connecting rod cap bolts.





3. Using the 2 removed connecting rod bolts, remove the connecting rod cap and lower bearing by wiggling the connecting rod cap right and left.

NOTE: Keep the lower bearing inserted with the connecting rod cap.

5. Clean the crank pin and bearings.
6. Check the crank pin and bearing for pitting and scratches.

NOTE: If the crank pin or bearing is damaged, replace the bearings. If necessary, replace the crankshaft.





7. Lay a strip of Plastigage across the crank pin.





8. Install the connecting rod cap with the 2 bolts, tighten in two steps as follows:
1st. step, tighten to 29 Nm (22 ft. lbs.).
2nd. step,turn an additional 90°.

NOTE: Do not turn the crankshaft.

9. Remove the 2 bolts, connecting rod cap and lower bearing.





10. Measure the Plastigage at its widest point.
Standard oil clearance:
Standard bearings: 0.023-0.041 mm (0.0009-0.0016 inch).
0.25 undersize bearings: 0.028-0.066 mm (0.0011-0.0026 inch).
Maximum oil clearance:
Standard bearings: 0.07 mm (0.0027 inch).
0.25 undersize bearings: 0.08 mm (0.0031 inch).
11. If the oil clearance is greater than maximum, replace the bearings.
12. If necessary, grind or replace the crankshaft





NOTE:
- If using a standard bearing, replace with one having the same number.
- If the number of the bearing cannot be determined, select the correct bearing by adding together the numbers imprinted on the connecting rod cap and crankshaft, then selecting the bearing with the same number as the total.
- There are 5 sizes of standard bearings, marked "1", "2", "3", "4", and "5" accordingly.
Reference:
Connecting rod big end inside diameter:
Mark "1" 55.025-55.031 mm (2.1663-2.1666 inch)
Mark "2" 55.031-55.037 mm (2.1666-2.1668 inch)
Mark "3" 55.037-55.043 mm (2.1668-2.1670 inch)
Crankshaft crank pin diameter:
Mark "0" 51.994-52.000 mm (2.0470-2.0472 inch)
Mark "1" 51.988-51.994 mm (2.0468-2.0470 inch)
Mark "2" 51.982-51.988 mm (2.0465-2.0468 inch)
Standard sized bearing center wall thickness:
Mark "1" 1.498-1.501 mm (0.0590-0.0591 inch)
Mark "2" 1.501-1.504 mm (0.0591-0.0592 inch)
Mark "3" 1.504-1.507 mm (0.0592-0.0593 inch)
Mark "4" 1.507-1.510 mm (0.0593-0.0594 inch)
Mark "5" 1.510-1.513 mm (0.0594-0.0596 inch)

13. Completely remove the Plastigage.

THRUST CLEARANCE






1. Using a suitable dial indicator, measure the thrust clearance while moving the connecting rods back and forth.
Standard thrust clearance: 0.250-0.402 mm (0.0098-0.0158 inch).
Maximum thrust clearance: 0.50 mm (0.0197 inch).
2. If the thrust clearance is greater than maximum, replace the connecting rod assembly(s).
3. If necessary, replace the crankshaft.
Connecting rod thickness: 25.898-25.950 mm (1.0196-1.0217 inch).