Detroit Diesel — Valve Lash Adjustments
Adjustments · Valve train
From a Detroit Diesel service manual — check it applies to your exact model before use.
Before you start
- The engine brake lash must also be set every time the valve lash is adjusted.
Procedure
- Turn engine OFF; steam clean the engine.
- Disconnect the starting power.
- Remove air cleaner, turbocharger inlet pipe/hose, and air cleaner housing.
- Remove the rocker cover.
- Bar the engine until cylinder No. 1 is at TDC compression stroke (J-46392).
- Using a feeler gauge, lash intake valves one, two and four to 0.4 mm (0.016 in).
- Lash exhaust valves one, three and five to 0.6 mm (0.024 in).
- Bar the engine over 360° until cylinder No. 6 is at TDC compression stroke.
- Lash intake valves three, five and six to 0.4 mm (0.016 in).
- Lash exhaust valves two, four and six to 0.6 mm (0.024 in).
- Torque the locknut valve adjusting screw to 50 N·m.
- Remove tools used; set the engine brake lash.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Intake valve lash: 0.4 mm (0.016 in)
- Exhaust valve lash: 0.6 mm (0.024 in)
- Valve adjusting screw locknut: 50 N·m (37 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.