Wrangler 4WD L4-150 2.5L VIN P MFI (1998)
face the front of the engine.
5. Install the lower bearing insert in the bearing cap. The lower insert must be dry. Place strip of Plastigage across full width of the lower insert at the
center of bearing cap. Plastigage must not crumble in use. If brittle, obtain fresh stock.
6. Install bearing cap and connecting rod on the journal and tighten nuts to 45 Nm (33 ft. lbs.) torque. DO NOT rotate crankshaft. Plastigage will
smear, resulting in inaccurate indication.
7. Remove the bearing cap and determine amount of bearing-to journal clearance by measuring the width of compressed Plastigage. Plastigage
should indicate the same clearance across the entire width of the insert. If the clearance varies, it may be caused by either a tapered journal, bent
connecting rod or foreign material trapped between the insert and cap or rod.
8. If the correct clearance is indicated, replacement of the bearing inserts is not necessary. Remove the Plastigage from crankshaft journal and
bearing insert. Proceed with installation.
9. If bearing-to-journal clearance exceeds the specification, install a pair of 0.0254 mm (0.001 inch) undersize bearing inserts. All the odd size
inserts must be on the bottom. The sizes of the service replacement bearing inserts are stamped on the backs of the inserts. Measure the clearance
as described in the previous steps.
10. The clearance is measured with a pair of 0.0254 mm (0.001 inch) undersize bearing inserts installed. This will determine if two 0.0254 mm (0.001
inch) undersize inserts or another combination is needed to provide the correct clearance.
11. FOR EXAMPLE: If the initial clearance was 0.0762 mm (0.003 inch), 0.025 mm (0.001 inch) undersize inserts would reduce the clearance by
0.025 mm (0.001 inch). The clearance would be 0.002 inch and within specification. A 0.051 mm (0.002 inch) undersize insert would reduce the
initial clearance an additional 0.013 mm (0.0005 inch). The clearance would then be 0.038 mm (0.0015 inch).
12. Repeat the Plastigage measurement to verify your bearing selection prior to final assembly.
13. Once you have selected the proper insert, install the insert and cap. Tighten the connecting rod bolts to 45 Nm (33 ft. lbs.) torque.
