John Deere — Check and Adjust Engine Valve Clearance
Adjustments · Cylinder head / valve train
From a John Deere operator's manual covering: 4039, 4045, 6059, 6068, RG4697. Check it applies to your exact model before use.
Applies to: John Deere 4039, John Deere 4045, John Deere 6059, John Deere 6068
Before you start
- Engine valve clearance MUST BE checked and/or adjusted with engine COLD
- Any time air intake system is opened, it must be checked for leaks before machine is returned to service
Procedure
- Remove rocker arm cover and crankcase ventilator hose.
- Remove plugs or cover plate from flywheel housing timing holes.
- Rotate engine in running direction (clockwise viewed from front) until No. 1 cylinder is at TDC compression stroke. Insert timing pin in flywheel.
- Check and adjust valve clearance to specifications.
- Tighten jam nut to 27 N-m (20 lb-ft) after adjusting valve clearance.
- Lock No. 1 piston at TDC compression stroke, adjust valves per firing order, turn crankshaft 360 degrees and adjust remaining valves.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Intake valve clearance: 0.35 mm (0.014 in.)
- Exhaust valve clearance: 0.45 mm (0.018 in.)
- Jam nut torque: 27 N-m (20 lb-ft)
- 3-cylinder FridayParts $49.20 firing order: 1-2-3 Amazon Amazon eBay
- 4-cylinder FridayParts $14.48 firing order: 1-3-4-2
- 6-cylinder FridayParts $54.99 firing order: 1-5-3-6-2-4
Full service-parts list: John Deere 4039 →, John Deere 4045 →, John Deere 6068 →
Source: John Deere operator's 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.