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Home›Repair guides›Engine Cylinder Head Torque Sequence - Four Cylinder D-Series

Hercules — Engine Cylinder Head Torque Sequence - Four Cylinder D-Series

For these Hercules models: D-1500, D-1700, D-198-ER, D-2000, D-2300, D-298-ER, D-3000, D-3400, OD Series.

Applies to: Hercules D 1500, Hercules D 1700, Hercules D 2000, Hercules D 2300, Hercules D 3400, Hercules Od Series

Before you start

  • Valve lash must be reset after cylinder head is re-torqued

Procedure

  1. Lubricate stud threads, nut threads, and nut seats with engine oil
  2. Tighten the cylinder head nuts to 45 ft-lbs in the specified sequence
  3. Tighten the nuts to 90 ft-lbs in the same sequence
  4. Tighten the nuts to 135 ft-lbs in the same sequence
  5. Tighten the specified nuts to 160/175 ft-lbs in the same sequence
  6. Start and run the engine until the coolant temperature is a minimum of 175 degrees Fahrenheit
  7. Shut the engine down and re-torque the cylinder head nuts to the final specified value while the engine is hot
  8. Reset valve lash after cylinder head is re-torqued

Tools required

  • torque wrench

Specs & torque values

  • torque 45 ft-lbs
  • torque 90 ft-lbs
  • torque 135 ft-lbs
  • torque 160/175 ft-lbs
  • final torque while engine hot

Source: manual:HERCULES Diesel D1700 D2000 D2300 D3000 D3400 Maintenance Manual.pdf. Figures and steps are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.