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Caterpillar 3406 C15 Engine Block Repair: ATC-8240 Professional Upper Deck Insert
Professional upper deck insert for Caterpillar 3406 C15 counterbore restoration.
The ATC-8240 Upper Deck Insert restores worn or damaged counterbores in Caterpillar 3406 and C15 blocks. Replacement for PT-8240/5P4173, this precision insert ensures proper liner protrusion and sealing for reliable heavy-duty performance.

The Critical Risks of Damaged Upper Deck in CAT Engines
Caterpillar 3406 and C15 engines face intense demands, but pitted or cracked upper deck counterbores lead to liner misalignment, leaks, and failures. Without inserts, repairs escalate costs.
- Liner protrusion issues – Worn ledges cause blow-by, requiring $1,000–$2,500 gasket jobs
- Sealing failures – Cracks allow contamination, costing $2,000–$4,000 cleanups
- Compression loss – Misaligned liners reduce power, leading to $1,500–$3,000 diagnostics
- Downtime losses – Extended repairs add $300–$600/hour in fleet idle
- Block damage – Severe pitting demands machining, totaling $2,000–$4,000
- Engine overhaul – Cascading failures require rebuilds ($5,000–$10,000)
What is the ATC-8240 Upper Deck Insert?
The ATC-8240 / PT-8240 Caterpillar 3406 / C15 Block Deck / Upper Insert is a precision insert that restores the upper counterbore ledge. With OD 6.665″ and height 0.205″, it's a direct replacement for PT-8240/5P4173, providing stable liner seating.
Designed for professional rebuilders, the ATC-8240 avoids excessive machining, ensures concentric surfaces, and supports long-term engine durability.
Complete Insert Specifications & Caterpillar Compatibility
Compatible Engines: Caterpillar 3406, C15
Dimensions: OD 6.665″, Height 0.205″
Function: Upper deck counterbore restoration, liner sealing
Material: High-quality for corrosion resistance
Replacement For: PT-8240, 5P4173
Application: Engine block rebuilds, deck repair
Shipping Weight: 1.00 lb (easy handling)
Professional Features & Engine Rebuild Benefits
✓ Precision Dimensions
6.665″ OD restores OEM ledge, preventing $1,000+ leaks.
✓ Corrosion Resistance
Material withstands environments, extending service life.
✓ Press-Fit Design
Stable installation for concentric liner alignment.
✓ OEM Replacement
Matches PT-8240/5P4173 for compliance.
✓ Cost Savings
Avoids excessive machining, saving $2,000+.
✓ Bulk Pricing
Discounts for 10+ units, ideal for shops.
Economic Impact: Block Repair ROI
When CAT Technicians Choose ATC-8240
- Caterpillar 3406 block deck repair
- C15 upper counterbore restoration
- Liner protrusion optimization
- PT-8240/5P4173 upgrades
- Heavy-duty diesel rebuilds
- Fleet engine shops
- Sealing integrity maintenance
Restore Decks Precisely. Protect CAT Engines. Prevent Failures.
Get ATC-8240 – $68.50Why Professional Shops Trust ATC-8240
CAT rebuilders rely on the ATC-8240 for its PT-8240 equivalence, precision dimensions, and ability to avoid $9,500–$19,500 in damages per failure. It offers stable seating, cost-effective repairs, and bulk pricing for shops.
From deck pitting to crack fixes, this insert keeps CAT engines reliable.
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