CAT C15 / 3406E Head Bolt Kit — 1241854 / 1241855, New

One kit covers every year ever made — including the 2005 BXS engines. CAT kept the same head bolt spec across the 3406E, C15, and C15 ACERT with one exception: the 2005 model year BXS engines used three different bolt types. Most kits on the market skip them. Ours includes all three bolt types, which makes this kit truly universal: whatever year your engine is, this is the kit.

Required on every head job. CAT head bolts are torque-to-yield — they stretch permanently when torqued and are single-use by design. Reusing stretched bolts is the fastest way to lose clamping force and blow a brand-new head gasket. If the head is coming off, these go in the trash and new ones go on.

Kit Includes

• (10) Long head bolts — OEM# 1241854 (8.5")

• (16) Short head bolts — OEM# 1241855 (7.6")

• (26) Hardened washers — OEM# 5H1504

• All three 2005 BXS-spec bolt types included — full coverage for the one year CAT changed the spec

Features

• Premium-grade materials, heat-treated for strength and durability

• Precision-machined to OEM specifications

• Designed to maintain clamping force under high cylinder pressure

Fitment

Every year of Caterpillar 3406E, C15, and C15 ACERT ever made — including 2005 BXS — plus C16 and C18 applications using these bolt specs. Send us your engine serial number (ESN) if you want fitment confirmed.

Pairs With

Doing the full job? You will also need:

• CAT C15 Cylinder Head, 2239250 (New, Universal)

• C15 / 3406E Spacer Plate (6I4421 — standard to .004\" under)

• C15 / 3406E Head Gasket Kit (2486740) — for head-only jobs; in-frame overhaul kits already include it

Frequently Asked Questions

Can I reuse my old head bolts?
No. These are torque-to-yield bolts — they stretch permanently the first time they are torqued. Reused bolts cannot hold spec clamping force, and the usual result is a blown head gasket within months.

Will this fit my year — even a 2005 BXS?
Yes. CAT changed the head bolt spec for the 2005 model year BXS engines only, which used three different bolt types. This kit includes all three, so it covers every 3406E, C15, and C15 ACERT ever made — 2005 BXS included. Send us your ESN if you want it confirmed.

How many bolts do I need for a C15 head?
This kit is the complete set for one head: 10 long, 16 short, plus 26 hardened washers.