John Deere 4045 / 6068 — Check and Adjust Valve Clearance
Adjustments · Valve train
For the John Deere 4045 / 6068, from the John Deere owner's manual.
Applies to: John Deere 4045, John Deere 6068
Before you start
- Valve clearance MUST BE checked and adjusted with engine COLD.
Procedure
- Disconnect NEGATIVE battery terminal to prevent accidental starting.
- Remove rocker arm cover and crankcase ventilator tube.
- Remove plastic plugs or cover plate from timing/rotation hole and timing pin hole.
- Rotate flywheel in running direction until No. 1 cylinder is at TDC compression; insert timing pin.
- Loosen jam nut on rocker arm adjusting screw.
- Turn adjusting screw until feeler gauge slips with a slight drag.
- Hold adjusting screw and tighten jam nut to 27 N.m (20 lb-ft).
- Recheck clearance after tightening jam nut; readjust as necessary.
- Replace rocker arm cover and crankcase ventilator tube.
Tools required
- JDE83 or JDG281A Flywheel Turning Tool Amazon
- JDG1571 Timing Pin Amazon
- Feeler gauge Amazon
- Screwdriver Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Intake Valve Clearance Adjustment (Engine Cold) - 0.36 mm (0.014 in.)
- Exhaust Valve Clearance Adjustment (Engine Cold) - 0.46 mm (0.018 in.)
- Rocker Arm Adjusting Screw Jam Nut - 27 N.m (20 lb-ft)
Full service-parts list: John Deere 4045 →, John Deere 6068 →
Source: John Deere owner'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.