Ford — Fitting Main or Connecting Rod Bearings with Plastigage
Repair & overhaul · Crankshaft bearings
From a Ford service manual covering: 140 CID, 2.3 LITRE, 2300 cc, LSG-423. Check it applies to your exact model before use.
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Before you start
- Do not turn crankshaft while Plastigage is in place.
Procedure
- Clean crankshaft journals; inspect journals and thrust faces for nicks, burrs or bearing pickup.
- If fitting main bearing in chassis, support crankshaft with jack under counterweight adjoining bearing.
- Place a piece of Plastigage on bearing surface across full width of bearing cap about 1/4 inch off center.
- Install cap and torque bolts to specifications; do not turn crankshaft.
- Remove cap and check width of Plastigage at widest point to get minimum clearance.
- If clearance exceeds limits on connecting rod bearings, try a 0.002 inch undersize bearing with standard bearings.
- If standard and 0.002 undersize bearings do not bring clearance within limits, refinish crankshaft journal and install undersize bearings.
- After fitting, remove Plastigage, apply light coat of engine oil, install bearing cap and torque to specifications.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Source: Ford service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.