Detroit Diesel — Exhaust Valve Bridge Adjustment
Adjustments · Exhaust Valves
From a Detroit Diesel service manual — check it applies to your exact model before use.
Before you start
- Loosening or tightening the locknut with the bridge in place may result in a bent bridge guide or bent rear valve stem.
Procedure
- Place the valve bridge in a vise or holding fixture J 21772 and loosen the locknut on the bridge adjusting screw.
- Install the valve bridge on the valve bridge guide.
- Press straight down on the pallet surface and turn the adjusting screw clockwise until it just touches the valve stem, then an additional 1/8 to 1/4 turn.
- Remove the valve bridge and place it in a vise; hold the adjustment screw and tighten the locknut to 20-25 lb-ft.
- Lubricate the valve bridge guide and valve bridge with engine oil.
- Reinstall the valve bridge in its original position.
- Place a .0015" feeler gage under each end of the valve bridge and check that both feeler gages are tight.
- Remove the valve bridge and reinstall it in its original position; adjust remaining bridges the same way.
- Swing the rocker arm assembly into position making sure the valve bridges are properly positioned on the rear valve stems.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Valve bridge locknut 20-25 FridayParts $42.95 lb-ft (27-34 N·m)
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.