John Deere — Torque-to-Yield Flanged-Head Cap Screws (Cylinder Head)
Repair & overhaul
From a John Deere service manual — check it applies to your exact model before use.
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Before you start
- Only ASTM Grade 180 flanged-head cap screws marked SPECIAL are recommended; ALWAYS use NEW cap screws - may be used only one time.
- DO NOT use multi-viscosity oils to lubricate cap screws; SAE30 is recommended.
- Cap screws MUST NOT be tightened more than a total of 270° ±5°.
Procedure
- Lubricate cap screws with clean SAE30 engine oil and install in their proper locations (arrow points toward front of engine).
- Tighten cap screw No. 17 to 80 N-m (60 lb-ft), then sequentially tighten all cap screws No. 1 through 26 to 80 N-m (60 lb-ft).
- Draw a line parallel to the crankshaft across the entire top of each cap screw head as a reference mark.
- Sequentially (No. 1 through 26) turn each cap screw 90°.
- Again sequentially (No. 1 through 26) turn each cap screw 90°.
- Finally sequentially turn each cap screw 90° so the line is as close as possible to perpendicular to the crankshaft; total turn from steps 4, 5 and 6 is 270° ±5°.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Initial 80 N-m (60 lb-ft)
- Total additional 270° ±5°
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.