Connecting Rod Bearing: Service and Repair

HOW TO SELECT PISTON AND BEARING


Description






- The identification grade stamped on each part is the grade for the dimension measured in new condition.
This grade cannot apply to reused parts.
- For reused or repaired parts, measure the dimension accurately. Determine the grade by comparing the measurement with the values of each selection table.
- For details of the measurement method of each part, the reuse standards and the selection method of the selective fitting parts, refer to the text.





HOW TO SELECT PISTON AND BEARING


Connecting Rod Bearing


WHEN NEW CONNECTING ROD AND CRANKSHAFT ARE USED
1. Apply connecting rod big end diameter grade stamped (D) on connecting rod side face to the row in the "CONNECTING ROD BEARING SELECTION TABLE".






A : Sample codes
B : Bearing stopper groove
C : Small-end diameter grade
E : Weight grade
F : Cylinder No.
G : Management code
H : Front mark
I : Management code






2. Apply crankshaft pin journal diameter grade stamped on crankshaft front side to the column in the "CONNECTING ROD BEARING SELECTION TABLE"

A : Journal diameter grade No. 1
B : Journal diameter grade No. 2
C : Journal diameter grade No. 3
D : Journal diameter grade No. 4
E : Pin diameter grade No. 1
F : Pin diameter grade No. 2
G : Pin diameter grade No. 3
H : Pin diameter grade No. 4
I : Pin diameter grade No. 5
J : Pin diameter grade No. 6
K : Identification


3. Read the symbol at the cross point of selected row and column in the "CONNECTING ROD BEARING SELECTION TABLE".
4. Apply the symbol obtained to the "CONNECTING ROD BEARING GRADE TABLE" to select connecting rod bearing.

WHEN CONNECTING ROD AND CRANKSHAFT ARE REUSED
1. Measure connecting rod big end diameter and crankshaft pin journal diameter. Refer to Inspection.
2. Correspond the measured dimension in "connecting rod big end diameter" row of "CONNECTING ROD
BEARING SELECTION TABLE".
3. Correspond the measured dimension in "crankshaft pin diameter" column of "CONNECTING ROD BEARING SELECTION TABLE".
4. Follow step 3 and later in "WHEN NEW CONNECTING ROD AND CRANKSHAFT ARE USED".

CONNECTING ROD BEARING SELECTION TABLE






CONNECTING ROD BEARING GRADE TABLE

Connecting rod bearing grade table : Refer to Specifications.


UNDERSIZE BEARING USAGE GUIDE
- When the specified connecting rod bearing oil clearance is not obtained with standard size connecting rod bearings, use undersize (US) bearings.
- When using undersize (US) bearing, measure the connecting rod bearing inner diameter with bearing installed, and grind crankshaft pin so that the connecting rod bearing oil clearance satisfies the standard.

CAUTION:
In grinding crankshaft pin to use undersize bearings, keep the fillet R (A) [1.5 - 1.7 mm (0.059 - 0.067 in)].






Bearing undersize table : Refer to Specifications.