Valve Lash & Overhead Caterpillar 3406E Verified Factory Specs

Caterpillar 3406E Valve Lash Specs & Overhead Adjustment (Cold Engine)

Factory OEM valve lash clearances, feeler gauge sizes, Jake brake slave setting, and overhead adjustment procedure for Caterpillar 3406E diesel engines.

Selected Heavy Diesel Engine

Engine:Caterpillar 3406E (5EK / 2WS / 1MM)

Displacement:14.6L

Firing Order:1-5-3-6-2-4

Locknut Torque:25 ft-lbs

Intake Valve Lash (Cold)

0.015 in

Feeler Blade: .015 in (0.38 mm)

Exhaust Valve Lash (Cold)

0.030 in

Feeler Blade: .030 in (0.76 mm)

Engine Brake (Jake) Lash

0.027 in

Feeler Blade: .027 in (0.69 mm)

2-Turn Crankshaft Adjustment Protocol

Firing Order: 1-5-3-6-2-4

Select engine stroke position below to highlight exact cylinders, valves, and injectors ready for adjustment:

Crankshaft Timing Pin Position

Install timing bolt in flywheel at TC Compression Stroke Cylinder 1

Intake Valves Ready

Cylinders: N/A

Exhaust Valves Ready

Cylinders: N/A

Engine Brakes / Injectors Ready

Cylinders: N/A

Locknut Torque: 25 ft-lbs (34 N·m)

Source: Caterpillar Service Manual SENR5580 (3406E Diesel Truck Engine Specifications)

Caterpillar 3406E Cold Valve Clearance Standards

Overhead adjustment must strictly be performed with coolant temperature below 140°F (60°C):

INTAKE VALVES (COLD):

0.015 in (0.38 mm)

Feeler gauge: Smooth sliding friction drag.

EXHAUST VALVES (COLD):

0.030 in (0.76 mm)

Feeler gauge: Smooth sliding friction drag.

Engine Brake (Jake) Slave Lash & Injector Preload Dimensions

Engine Brake Slave Clearance: 0.027 in (0.69 mm)

Injector Preload / Height: 78.0 ± 0.2 mm using Cat 9U-7227 timing gauge

2-Turn Setting Order: TDC Compression Cylinder 1 -> Adjust Int (1, 2, 4), Exh (1, 3, 5). Rotate 360° to TDC 6 -> Adjust Int (3, 5, 6), Exh (2, 4, 6).

Locknut Torque & Maintenance Precautions

Always hold the valve adjustment screw stationary with a screwdriver or hex key while torquing the jam locknut to factory specification. Re-check clearance with feeler blade after final tightening to ensure screw did not turn.

Frequently Asked Questions & OEM Service Guidelines

Verified answers according to official factory service literature and heavy-duty maintenance procedures:

Q: What is the final torque stage on a Cat 3406E cylinder head?

The final stage requires torquing all 38 bolts in numerical sequence to 450 lb-ft (610 N-m), followed by a mandatory verification pass at 450 lb-ft.

Q: What are the cold valve lash clearances for a Cat 3406E?

Intake valve lash is 0.015 inches (0.38 mm) and exhaust valve lash is 0.030 inches (0.76 mm) measured cold when engine coolant temperature is below 140 F (60 C).

Related Heavy Diesel Engineering Tools

Cross-reference other factory specifications and diagnostic tools for commercial diesel engines:

Pillar 3 →

Valve Lash & Overhead

Intake, exhaust, & Jake brake clearances.

Pillar 1 →

Oil & Coolant Sump

Standard vs deep pan fill volumes.

Pillar 4 →

Head Bolt Torque

Torque-to-yield angle stages & sequences.

Pillar 2 →

SPN Fault Code Lookup

J1939 fault diagnostics & sensor pins.

Technical Reference Citation: Caterpillar Service Manual SENR5580 (3406E Diesel Truck Engine Specifications)

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