Detroit Diesel — Exhaust Valve Bridge Adjustment (Four-Valve Cylinder Heads)

Adjustments

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

Procedure

1. Remove valve rocker covers, injector fuel pipes, and rocker arm bracket bolts; move rocker arms away from the exhaust valve bridge.
2. Remove the exhaust valve bridge.
3. Place bridge in vise or holding fixture J 21772 and loosen the lock nut on the bridge adjusting screw.
4. Install the bridge on the bridge guide.
5. Press straight down on the pallet surface; turn adjusting screw clockwise until it just touches the valve stem, then 1/8 to 1/4 turn more.
6. Tighten the lock nut finger tight.
7. Remove bridge, hold screw with a screwdriver, and tighten lock nut to 25 lb-ft with a torque wrench.
8. Lubricate the bridge guide and bridge pilot with engine oil.
9. Reinstall the bridge in its original position.
10. Place a .0015 in feeler gage under each end of the bridge; both feeler gages must be tight when pressing down.
11. Adjust the remaining bridges the same way.
12. Swing the rocker arm assembly into position with bridges properly positioned on rear valve stems.
13. Tighten rocker arm bracket bolts to 90-100 lb-ft torque.
14. Align and connect fuel pipes to injectors and fuel connectors; tighten with socket J 8932 to 12-15 lb-ft.

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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