John Deere — Torque-to-Yield Flanged-Head Cap Screws—Grade 180 Marked SPECIAL Serial Number ( —199,999)
Repair & overhaul · Cylinder head cap screws
From a John Deere service manual — check it applies to your exact model before use.
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Before you start
- DO NOT use multi-viscosity oils to lubricate cap screws.
- If a cap screw is accidentally tightened more than 90° in any one sequence, DO NOT loosen cap screw but make adjustments in the next tightening sequence.
- 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 proper locations.
- Tighten cap screw No. 17 to 80 N·m (60 lb-ft).
- Sequentially tighten all cap screws Nos. 1 through 26 to 80 N·m (60 lb-ft).
- Draw a line parallel to crankshaft across top of each cap screw head.
- Sequentially turn each cap screw 90° to perpendicular to crankshaft.
- Again sequentially turn each cap screw 90° to parallel to crankshaft.
- Finally sequentially turn each cap screw 90° so line is as close as possible to perpendicular to crankshaft.
- Total amount of turn from final three steps is 270° ± 5°.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Cylinder head flanged-head SPECIAL cap screws initial torque: 80 N·m (60 lb-ft)
- Total turn: 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.