Replacement Core Plug for Caterpillar ® 3406 Applications Cup Type – 1.25" Diameter OEM Cross References: 3B645

1 x Cup Plug 1.25″

Engine S/N: Caterpillar 3406 A/B/C | 3B645 Specs 1.25″

Application & Fitment

• Engine Make: Caterpillar
• Engine Model / Application: 3406

Confirm the original part number and engine identification before ordering. Where applicable, also verify serial-number range, production year, piston style, bearing size or other configuration notes shown in the product information.

Part Numbers & Cross References

• OEM Cross Reference: 3B645
• Interstate-McBee Reference: M-3B645

Need Help Confirming Fitment?

Use the engine model, serial number and original part number when checking compatibility. For kits and sets, review the complete component breakdown above before ordering because contents can vary by engine configuration.