The LS-8704 thread insert restores stripped or damaged bolt holes on Caterpillar 3406 engine blocks—3/4"-16 internal × 7/8"-16 external threads, 3-1/4" length—delivers strong, reliable repair for head bolt, liner bolt, or deck bolt threads without block replacement.

The Expensive Consequences of Stripped Bolt Holes on Cat 3406 Engines

Stripped or damaged deck threads (head bolts, liner bolts) force expensive options: oversized bolts, heli-coil attempts, block machining, or full block replacement—leading to downtime, misaligned heads, or gasket failures.

• Heli-coil or thread repair failure – $500–$2,000 rework
• Head gasket / alignment issues – $1,500–$5,000 repeat service
• Cylinder head removal & reinstall – $2,000–$7,000 labor & parts
• Engine block replacement – $8,000–$18,000+ new/short block
• Downtime & lost revenue – 7–30 days ($800–$3,000/day fleet loss)
• Rework & comebacks — Extra 30–100 hours at $150–$350/hr

What is the LS-8704 Thread Insert?

The LS-8704 Caterpillar 3406 Bolt Hole Thread Insert is a high-strength repair insert with 3/4"-16 internal threads and 7/8"-16 external threads, 3-1/4" overall length—designed specifically to restore stripped or damaged bolt holes in Cat 3406 engine blocks.

Perfect for diesel rebuild shops, Cat specialists, and fleet maintenance, it provides OEM-strength threads, allows standard bolt use, and saves blocks from replacement—ideal for head bolt, liner bolt, or deck bolt repairs.

Complete Insert Specifications & Cat 3406 Compatibility

Professional Features & Engine Block Benefits

Economic Impact: LS-8704 ROI for Shops

Scenario	Cost Impact
LS-8704 repair insert	$56.00 (single) – $32.48 (bulk)
Heli-coil / thread chase failure	$500–$2,000
Cylinder head rework	$2,000–$7,000
Engine block replacement	$8,000–$18,000
Total stripped hole cost	$10,500–$27,000 per engine
LS-8704 ROI (first repair)	188–482X return on investment

When Cat 3406 Techs & Shops Choose LS-8704

• Caterpillar 3406 stripped deck / head bolt holes
• 3406 liner bolt thread repair
• Cat engine block salvage & rebuild
• Heavy-duty diesel machine shops
• Fleet maintenance on 3406-powered trucks
• Head gasket & top-end repair jobs
• Cost-effective thread restoration

Why 3406 Rebuilders Trust LS-8704

Caterpillar 3406 specialists rely on the LS-8704 for its precise dual-thread design, full-length engagement, and ability to salvage blocks that would otherwise cost $10K–$27K to replace. It restores factory-strength threads and keeps engines in service.

From heavy-haul rebuilds to fleet shops, this insert turns damaged blocks into profitable repairs.

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