Connecting Rod Bearing: Testing and Inspection

CONNECTING ROD THRUST CLEARANCE



1. Using a suitable dial indicator, measure the thrust clearance while moving the connecting rods back and forth.

Std. thrust clearance: 0.250 - 0.402 mm (0.0098 - 0.0158 in.).
Max. thrust clearance: 0.50 mm (0.0197 in.)

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 in.).

CONNECTING ROD BEARING 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 Plastigauge 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 (300 kg.cm, 22 ft.lb).
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 Plastigauge at its widest point.

Std. oil clearance:
Std. bearings: 0.023 - 0.041 mm (0.0009 - 0.0016 in.).
0.25 undersize bearings: 0.028 - 0.066 mm (0.0011 - 0.0026 in.).

Max. oil clearance:
Std. bearings: 0.07 mm (0.0027 in.).
0.25 undersize bearings: 0.08 mm (0.0031 in.).

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.

Connecting Rod Big End Inside Diameter
Mark "1" 55.025 - 55.031 mm (2.1663 - 2.1666 in.).
Mark "2" 55.031 - 55.037 mm (2.1666 - 2.1668 in.).
Mark "3" 55.037 - 55.043 mm (2.1668 - 2.1670 in.).

Crankshaft Crank Pin Diameter
Mark "0" 51.994 - 52.000 mm (2.0470 - 2.0472 in.).
Mark "1" 51.988 - 51.994 mm (2.0468 - 2.0470 in.).
Mark "2" 51.982 - 51.988 mm (2.0465 - 2.0468 in.).

Std. Sized Bearing Center Wall Thickness
Mark "1" 1.498 - 1.501 mm (0.0590 - 0.0591 in.).
Mark "2" 1.501 - 1.504 mm (0.0591 - 0.0592 in.).
Mark "3" 1.504 - 1.507 mm (0.0592 - 0.0593 in.).
Mark "4" 1.507 - 1.510 mm (0.0593 - 0.0594 in.).
Mark "5" 1.510 - 1.513 mm (0.0594 - 0.0596 in.).

13. Completely remove the Plastigauge.