Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Main Bearing Oil Clearance

MAIN BEARING OIL CLEARANCE
Method by Calculation





^ Install main bearings to cylinder block and main bearing caps, and tighten main bearing cap bolts with main bearing to the specified torque.
^ Measure the inner diameter of main bearing with bore gauge.

(Bearing clearance) = (Main bearing inner diameter) - (Crankshaft main journal diameter)
Standard
No . 1 and 5 journal : 0.001 - 0.011 mm (0.00004 - 0.0004 inch)
No. 2, 3 and 4 journal : 0.007 - 0.017 mm (0.0003 - 0.0007 inch)
Limit
No . 1 and 5 journal : 0.021 mm (0.0008 inch)
No. 2, 3 and 4 journal : 0.027 mm (0.0011 inch)
^ If the calculated value exceeds the limit, select proper main bearing according to main bearing inner diameter and crankshaft main journal diameter to obtain the specified bearing oil clearance.

Method of Using Plastigage
^ Remove oil and dust on crankshaft main journal and the surfaces of each bearing completely.
^ Cut plastigage slightly shorter than the bearing width, and place it in crankshaft axial direction, avoiding oil holes.
^ Install main bearings to cylinder block and main bearing caps, and tighten main bearing bolts with main bearing to the specified torque.

CAUTION: Do not rotate crankshaft.





^ Remove main bearing caps and bearings, and using scale on plastigage bag, measure the plastigage width.

NOTE: The procedure when the measured value exceeds the limit is same as that described in the "Method by Calculation".