Crankshaft/Connecting Rod Bearing - Selection
BULLETIN NUMBER ISSUE DATE GROUPSB86-01-002 May 30, 1986 ENGINE
MODELS AFFECTED
All I-Mark (JT) models.
SERVICE INFORMATION
Crankshaft main and connecting rod bearing inserts are available in varying thicknesses. Pages 01-47 and 01-48 of the 1986 I-Mark (JT) Workshop Manual
contain an explanation of the bearing insert color coding and the size markings on the engine block, crankshaft and connecting rods. That information is reproduced here. These bearing selection procedures can be used when servicing 1985 models, although the information was not included in the 1985 I-Mark (JT) Workshop Manual.
SERVICE PROCEDURE
CONNECTING ROD:
Con-rod bearing selection Select and install the new connecting rod bearings, paying close attention to the connecting rod big end diameter size mark.
Note: Take care not to confuse the alignment mark and the size mark during the installation procedure.
(1) Big end Bore Crankshaft Connecting Rod Color of Oil Clearance
Size Mark
Diameter (mm) Pin Diameter (mm) Bearing Thickness Size Mark (mm)
(mm)
I 42.994-43.000 (1.508-1.512) Blue 0.025-0.054
II 42.988-42.993 39.930-39.945 (1.504-1.508) Black 0.027-0.056
III 42.982-42.987 (1.500-1.504) Brown 0.029-0.058
Under Size
39.680-39.695 -
0.25
42.982-43.000 Stamp of 0.025-0.078
Under Size
39.430-39.445 - Size Mark
0.50
CRANKSHAFT BEARING:
CRANK SHAFT BEARING SELECTION
When installing new crankshaft bearings or replacing old bearings, refer to the below selection table.
CRANKSHAFT BEARING:
Crankshaft bearing
Select and install the new crankshaft bearings, paying close attention to the cylinder body journal hole
(1) diameter size mark and the crankshaft journal (2) diameter size mark.
JOURNAL BEARING:
Note: Only the No. 3 journal bearing lower side is grooveless. Other bearings, although identical in classification, are grooved. Pay close attention to this distinction during the installation procedure.
(1) Cylinder Body Crank Shaft Crank Shaft Crank Shaft
Size mark Main Journal Main Journal Size Bearing Bearing Oil Clearance
Diameter (mm) Diameter (mm) Mark Size Mark Size Mark ( mm)
(Upper Side) ( Lower Side) ( Reference)
47.918-47.928 - - Blue Blue 0.022-0.048
1 51.992-52.000 47.929-47.938 - 0.020-0.046
47.918-47.928 - - Black Black 0.022-0.048
2 51.984-51.991 47.929-47.938 - 0.020.046
47.918-47.928 - - Brown Brown 0.022-0.048
3 51.976-51.983 47.929-47.938 - 0.020-0.046
Under Size
0.25 51.976-52.000 47.668-47.688 Stamp of Size Stamp of Size 0.020-0088
47.418-47 438
Under Size 0.50