Facts About Generators
GeneratorsDirectoryCompareRepairEnginesControllersPartsManufacturersGuides
Search models or part #
Home›Repair guides›John Deere›Valve — Clearance Adjustment

John Deere 9.0 L Diesel Engines — Valve — Clearance Adjustment

Adjustments · Cylinder head and valve train

For the John Deere 9.0 L Diesel Engines, from the John Deere service manual.

Applies to: John Deere 6090H engine

Before you start

  • Valve clearance MUST BE checked and adjusted with engine COLD.
  • Visually inspect contact surfaces of valve tips and rocker arm wear pads; replace parts showing visible damage.
  • When reinstalling rocker arm cover, DO NOT reuse gasket.

Procedure

  1. Disconnect NEGATIVE (—) battery terminal and remove rocker arm cover with vent tube.
  2. Remove plastic plug from cylinder block bores and install JDG820 Flywheel Turning Tool and Timing Pin.
  3. Rotate engine with the flywheel turning tool until timing pin engages timing hole in flywheel.
  4. If rocker arms for No. 1 (front) cylinder are loose, engine is at No. 1 TDC-Compression; if No. 6 is loose, rotate one full revolution.
  5. Push the rocker arm foot forward for easier feeler gauge access.
  6. Use a bent feeler gauge to check clearance on Nos. 1, 3 and 5 exhaust valves and Nos. 1, 2 and 4 intake valves.
  7. Loosen lock nut; turn adjusting screw until feeler gauge slips with a slight drag.
  8. Hold adjusting screw with a screwdriver and tighten lock nut to specification.
  9. Recheck clearance after tightening lock nut; readjust as necessary.
  10. Rotate flywheel 360° until No. 6 piston is at TDC of its compression stroke.
  11. Check and adjust clearance on Nos. 2, 4 and 6 exhaust and Nos. 3, 5 and 6 intake valves.
  12. Install new rocker arm cover gasket, then install cover with vent tube.
  13. Tighten cap screws in sequence shown to 35 N·m; after 10 minutes re-torque in sequence.
  14. Connect main engine wiring harness.

Tools required

  • JDG820 Flywheel Turning Tool and Timing Pin Amazon
  • bent feeler gauge Amazon
  • torque wrench Amazon

Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.

Specs & values

  • Intake valve clearance (cold) 0.13—0.23 mm (0.005—0.009 in.)
  • Exhaust valve clearance (cold) 0.58—0.69 mm (0.023—0.027 in.)
  • Valve adjusting screw lock nut 27 N·m (20 lb-ft)
  • Rocker arm cover cap screws 35 N·m (26 lb-ft)

Full service-parts list: John Deere 6090H engine →

Source: John Deere 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.

More John Deere repair guides →