Detroit Diesel — Assemble Piston And Connecting Rod (Cross-Head Piston)

Repair & overhaul · Piston and Piston Rings

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

Procedure

1. Install the bearing (bushing) in the piston crown (install before assembling the piston skirt and crown).
2. Lubricate the fluoroelastomer seal ring liberally with STP and install it in the piston crown; avoid excessive stretching.
3. Compress the former seal ring with ring compressor J 24421 and push the skirt into position on the crown.
4. Check that the seal ring is free in the groove around the full 360° circumference.
5. Lubricate the piston pin with the clean engine oil/STP mix and install it in the crown and skirt.
6. Install the spacers on the two 1/2"-20 x 2-1/4" connecting rod to piston pin attaching bolts.
7. Lubricate the threads and the underside of the bolt heads with International Compound No. 2.
8. Insert the bolts through the end of the connecting rod and thread finger-tight into the piston pin; clamp the rod in a vise.
9. Tighten the bolts to 35-45 lb-ft followed by 60° to 80° additional rotation.
10. Place a new piston pin retainer in position and seat it with installer J 24274-B.
11. Install the second piston pin retainer in the same manner.
12. Check each retainer for proper sealing with leak detector J 23738 and vacuum cup J 24629.

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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