Ford CSG-649 — Fitting Main or Connecting Rod Bearings with Plastigage

Adjustments · Crankshaft main and connecting rod bearings

For the Ford CSG-649, from the Ford service manual.

Applies to: Ford CSG-649

Procedure

1. Clean the crankshaft journals; inspect journals and thrust faces for nicks, burrs or bearing pickup.
2. If fitting a main bearing, position a jack under the counterweight adjoining the bearing being checked; do not place jack under front post.
3. Place a piece of Plastigage on the bearing surface across the full width of the bearing cap, about 1/4 inch off center.
4. Install the cap and torque the bolts to specifications; do not turn the crankshaft while Plastigage is in place.
5. Remove the cap and check the width of the Plastigage at the widest and narrowest points with the scale.
6. If clearance exceeds limits, try 0.001 or 0.002 inch undersize bearings in combination with standard bearings.
7. Remove the Plastigage and apply a light coat of engine oil to the journal and bearings; install the cap and torque bolts to specifications.
8. Repeat for the remaining bearings that require replacement.

Full service-parts list: Ford CSG-649 →

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.

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