Detroit Diesel — Inspection of Cylinder Block

Testing & diagnosis

From a Detroit Diesel service manual — check it applies to your exact model before use.

Procedure

1. Inspect all machined surfaces for nicks or burrs.
2. Inspect tapped holes for thread damage.
3. Inspect block for loose or damaged dowel pins.
4. Measure dowel extension from ends of block.
5. Measure extension of dowels retaining the crankshaft thrust washers.
6. Inspect dowel pins in rear main bearing cap for looseness or damage.
7. Check head contact surfaces for flatness with straight edge and feeler gage.
8. Measure distance from crankshaft centerline to top of head surface.
9. Clean counterbores and check counterbore depth.
10. Inspect cylinder head retaining bolt holes for damaged threads.
11. Check main bearing bore diameter and misalignment.
12. Measure block bores at positions A/B/C/D and check taper and out-of-roundness.

Source: Detroit Diesel 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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