Main Bearing Service

Plastigage method is used to determine connecting rod and main bearing journal clearances. Standard or undersize crankshafts are marked red or blue. Color coded inserts must agree with crankshaft color code (See Fig 1 & Fig 2). The following table shows color code and undersizes available:

Fig 1: View Showing Original Crankshaft Marks

Courtesy of BMW OF NORTH AMERICA, INC.

MAIN BEARING JOURNAL

Application	Red In. (mm)	Blue In. (mm)
Original	2.1646-2.1650 (54.98-54.99)	2.1642-2.1646 (54.97-54.98)
1st Stage	2.1547-2.1551 (54.73-54.74)	2.1543-2.1547 (54.72-54.73)
2nd Stage	2.1449-2.1453 (54.48-54.49)	2.1445-2.1449 (54.47-54.48)
3rd Stage	2.1350-2.1354 (54.23-54.24)	2.1346-2.1350 (54.22-54.23)

Fig 2: View Showing Undersize Crankshaft Marks

Courtesy of BMW OF NORTH AMERICA, INC.

CONNECTING ROD JOURNAL

Application	Diameter In. (mm)
Original	1.8890-1.8894 (47.98-47.99)
1st Stage	1.8787-1.8791 (47.72-47.73)
2nd Stage	1.8681-1.8697 (47.45-47.49)
3rd Stage	1.8592-1.8598 (47.22-47.24)