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Caterpillar 3406E / 3456 Engine

The Caterpillar 3406E / 3456 is a turbocharged engine. It powers generator sets from Caterpillar, including the 3456 GENERATOR SET CCB.

Also known as: Caterpillar 3406E / 3456

Part of the Caterpillar 3406E engine family — 3 variants share parts & fitment.

On this pageService parts Specs Generator sets Maintenance Filter cross-reference FAQ Torque & specs Procedures

Service parts for the 3406E / 3456

The cheapest captured merchant offer per filter — see the full cross-reference below for every OEM/aftermarket option.

Fuel system

1 required

1165436Fuel filtersee priceAmazon

Oil system

1 required

0773673Oil filterfind

Prices captured from merchant listings; some links are affiliate links. Verify against your serial number before ordering.

Engine specifications

Aspiration	Turbocharged

Generator sets powered by this engine

Caterpillar 3456 GENERATOR SET CCB

How to read your Caterpillar engine serial & model number →

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Fuel filter			—
Oil filter			—

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service specifications

Type	Item	Value	Unit	Condition
Clearance	Connecting rod bearing clearance (max permissible, used bearings)	0.20	mm (0.008 inch)
Clearance	Connecting rod bearing clearance (new bearings)	0.062 to 0.160	mm (0.0024 to 0.0063 inch)
Clearance	Crankshaft end play (max permissible, used thrust plates)	0.89	mm (0.035 inch)
Clearance	Crankshaft end play (new thrust plates)	0.15 to 0.55	mm (0.006 to 0.022 inch)
Clearance	Crankshaft main bearing clearance (max permissible, used bearings)	0.25	mm (0.010 inch)
Clearance	Crankshaft main bearing clearance (new bearings)	0.091 to 0.186	mm (0.0036 to 0.0073 inch)
Clearance	Dowel protrusion from crankshaft face	4.1 + 0.5	mm (0.16 + 0.02 inch)
Clearance	Maximum dowel length out of crankshaft face	6.4	mm (0.25 inch)
Clearance	Valve guide bore surface diameter	35.00 + 0.50	mm (1.378 + 0.020 inch)
Other	Unit injector height (cylinders 1, 2, 4)	78.0 + 0.2	mm	measured from top of unit injector to machined ledge of fuel injector body, using 9U-7227 gauge
Other	Unit injector height (cylinders 3, 5, 6)	78.0 + 0.2	mm	measured from top of unit injector to machined ledge of fuel injector body, using 9U-7227 gauge
Torque	Atmospheric pressure sensor	10 + 2	N-m (90 + 20 lb in)
Torque	Camshaft gear / bearing bolts	30 + 7	N-m (22 + 5 lb ft)
Torque	Connecting rod bearing cap bolts (initial)	90 + 8	N-m (65 + 6 lb ft)	then additional 90 + 5 degrees (1/4 turn)
Torque	Coolant temperature sensor	20 + 3	N-m (15 + 2 lb ft)
Torque	Electronic Control Module mounting nuts	30 + 15	N-m
Torque	Electronic unit injector rocker arm to head bolts (initial)	50 + 10	N-m (37 + 7 lb ft)
Torque	Engine oil cooler bolt	39 + 3	N-m (29 + 2 lb ft)
Torque	Engine oil cooler front cover bolt	215 + 40	N-m
Torque	Engine oil filter base bolts	55 + 10	N-m (41 + 7 lb ft)
Torque	Engine oil pressure sensor	10 + 2	N-m (88 + 18 lb in)
Torque	Exhaust manifold nuts (numeric sequence)	38 + 5	N-m
Torque	Exhaust manifold shield nuts	25 + 7	N-m (18 + 5 lb ft)
Torque	Exhaust manifold studs in cylinder head	35 + 5	N-m (26 + 4 lb ft)
Torque	Fan drive allen head screws	2.25 + 0.25	N-m (20 + 2 lb in)
Torque	Flywheel bolts	270 + 40	N-m
Torque	Front housing bolts, step a (numeric sequence)	100 + 20	N-m (74 + 15 lb ft)
Torque	Front housing bolts, step b	40 + 10	N-m (30 + 7 lb ft)
Torque	Front housing bolts, step c (final, first pass)	135 + 20	N-m (100 + 15 lb ft)
Torque	Front housing bolts, step d (final, second pass)	55 + 10	N-m (41 + 7 lb ft)
Torque	Fuel filter base plugs	100 + 15	N-m (74 + 11 lb ft)
Torque	Fuel temperature sensor	20 + 5	N-m
Torque	Injector hold-down bolt cap nuts	2.5 + 0.25	N-m (22 + 2 lb in)
Torque	Inlet air temperature sensor	47 + 9	N-m (35 + 7 lb ft)
Torque	Main bearing cap bolts (initial, both sides)	260 + 14	N-m (190 + 10 lb ft)	then additional 120 + 5 degrees (2 flats) each side
Torque	Rocker arm and shaft bolts	55 + 10	N-m (41 + 7 lb ft)
Torque	Speed/timing sensor	15 + 3	N-m (11 + 2 lb ft)
Torque	Turbocharger V-band clamp nuts	14 + 1	N-m (10 + 1 lb ft)
Torque	Turbocharger exhaust manifold bolts	55 + 9	N-m
Torque	Turbocharger outlet pressure sensor	25 + 6	N-m (18 + 4 lb ft)
Torque	Unit injector adjusting screw locknut	100 + 10	N·m	hold adjusting screw in position while tightening
Torque	Unit injector adjusting screw locknut	74 + 7	lb ft	hold adjusting screw in position while tightening
Torque	Valve mechanism cover base bolts	18 + 3	N-m (13 + 2 lb ft)
Torque	Valve mechanism cover button head screws	13 + 3	N-m (10 + 2 lb ft)
Torque	Vibration damper and pulley bolts	109 + 15	N-m (80 + 11 lb ft)
Torque	Water pump bolts (step 1)	50 + 9	N-m (37 + 7 lb ft)
Torque	Water pump bolts (step 2)	9 + 3	N-m (80 + 27 lb in)

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

Electronic Unit Injector - Adjust adjustment

Tools: 9U-7227 Injector Height Gauge

Put the No. 1 piston at the top center position on the compression stroke.
Use the 9U-7227 injector height gauge to obtain a dimension of 78.0 + 0.2 mm (3.07 + 0.01 inch).
Measure from the top of the unit injector to the machined ledge of the fuel injector body.
Turn the unit injector adjusting screw clockwise until the correct height is obtained.
Hold the adjusting screw in this position and tighten the locknut to 100 + 10 N·m (74 + 7 lb ft).
For cylinders 1, 2, and 4, remove the timing bolt and turn the flywheel 360 degrees in the direction of engine rotation.
Engine rotation is counterclockwise as viewed from the flywheel end; this puts No. 1 piston at top center on the exhaust stroke.
Repeat Steps 3 through 4.
Remove the timing bolt from the flywheel and reinstall the valve mechanism cover.

Crankshaft - Install repair

Tools: 1H-3110 Bearing Puller, 8B-7560 Step Plate, 9U-6600 Hand Hydraulic Pump, 1H-3108 Push-Puller Leg, 1H-3107 Bearing Puller, 3H-0468 Puller Plate, 3H-0465 Push-Puller Plate, 1P-0820 Hydraulic Puller, 5B-0637 Nut, 8S-6586 Forcing Screw, 5P-0944 Dowel Puller Group, 5P-0939 Dowel Extractor

Install pin in crankshaft (max dowel length out of face 6.4mm/0.25in)
Install dowel in crankshaft (protrusion 4.1 +/-0.5 mm / 0.16+/-0.02 inch)
Heat crankshaft gear and install with keyway aligned to dowel, timing mark V facing away from crankshaft
Install upper main bearing halves dry (for clearance check) in cylinder block
Lift and install crankshaft (approx. 159 kg / 350 lb) aligning V marks on crankshaft gear and cluster gear
Install connecting rod caps
Install main bearing caps and bolts

Crankshaft Main Bearings - Install repair

⚠ If crankshaft turned wrong direction, bearing tab can damage cylinder block/crankshaft

Tools: 2P-5518 Bearing Tool, 8T-5096 Dial Indicator

Install new upper main bearings using bearing tool in crankshaft oil hole, turning crankshaft to seat bearing (non-tab end first)
Install new crankshaft main bearings in main bearing caps
Check crankshaft main bearing clearances (0.091-0.186 mm new; max 0.25 mm used)
Apply clean engine oil on bolts; install thrust plates at No. 4 main bearing with 'Block Side' toward block
Install main bearing caps and bolts, ensure cap numbers match block and arrows face front
Tighten bolt on bearing tab side to 260 + 14 N-m (190 + 10 lb ft), then opposite side to same torque
Mark bolts and caps; tighten opposite side an additional 120 + 5 degrees (2 flats), then tab side same
Check crankshaft end play with dial indicator (0.15-0.55 mm new thrust plates; max 0.89 mm used)

Engine Oil Pump - Remove repair

⚠ Be prepared to collect fluid with suitable containers

Start by removing engine oil pan
Remove bolts and remove engine oil pump

Exhaust Manifold - Remove and Install repair

Tighten studs in cylinder head to 35 + 5 N-m (26 + 4 lb ft)
Tighten manifold nuts in numeric sequence to 38 + 5 N-m
Tighten shield nuts to 25 + 7 N-m (18 + 5 lb ft)

Flywheel - Install repair

Install flywheel
Tighten bolts to 270 + 40 N-m

Front Cover / Housing (Front) - Install repair

Tighten bolts 1 through numeric sequence to 100 + 20 N-m (74 + 15 lb ft)
Tighten bolt 10 sequence to 40 + 10 N-m (30 + 7 lb ft)
Retighten bolt 1 sequence to 135 + 20 N-m (100 + 15 lb ft)
Retighten bolt 10 sequence to 55 + 10 N-m (41 + 7 lb ft)

Fuel Filter Base - Assemble repair

⚠ Check O-ring condition; replace if worn or damaged

Install O-ring seals on check valve
Install check valve in fuel filter base
Install O-ring seals on bypass valve
Install bypass valve in fuel filter base

Fuel Filter Base - Disassemble repair

Remove check valve from fuel filter base
Remove O-ring seals from check valve
Remove bypass valve from fuel filter base
Remove O-ring seals from bypass valve

Fuel Filter Base - Install repair

Install fuel filter base with bolts
Install fuel filter on fuel filter base per filter's direction markings
Connect tube assembly to fuel filter base
Connect hose assemblies to fuel filter base
Connect harness assembly to fuel temperature sensor
Turn fuel supply to ON position
Remove air from system per Testing and Adjusting, Fuel System - Prime

Fuel Filter Base - Remove repair

Tools: 185-3630 Strap Wrench, 9U-7072 Tapered Cap/Plug, 9U-7070 Tapered Cap/Plug

Turn fuel supply to OFF position
Disconnect harness assembly from fuel temperature sensor
Disconnect hose assemblies from fuel filter base
Disconnect tube assembly from fuel filter base
Use strap wrench (Tool A, 185-3630) to remove fuel filter from filter base
Remove bolts fastening fuel filter base to cylinder block, remove fuel filter base

Fuel Priming Pump - Remove and Install repair

⚠ Be prepared to collect fluid with suitable containers before opening compartment

Remove bolt (1) and bolt (4); remove fuel priming pump (3) from fuel filter base (2)
Remove gasket (5) for the fuel priming pump and fuel filter base
Install: ensure gasket (5) is in position
Put fuel priming pump (3) in position on fuel filter base (2)
Install bolt (1) and bolt (4)

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Parts cataloged across the Caterpillar 3406E family

Part #	Description	Category
9U-7227	Injector Height Gauge	Injector height gauge
101215531	Engine Valve Lash - Inspect/Adjust	Service part / kit

Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.

Filters for this engine

Fuel filter: Caterpillar 1165436 Caterpillar 2568753 Caterpillar 5134490 Caterpillar 3089679 Caterpillar 3I1333 Caterpillar 1110716 Caterpillar 3I1305 Caterpillar 494145823
Oil filter: Caterpillar 0773673 Caterpillar E38874 Caterpillar 3I1171 Caterpillar 2P4005 Donaldson P550008 Donaldson P552518 Donaldson P550335 Donaldson P554005

Cross-referenced via Donaldson + OEM/engine-maker interchange — options to verify against your serial number, not confirmed for every exact variant.

Also used in

Case/Case Ih LION — Tractor
Case/Case Ih PANTHER — Tractor
Caterpillar 740 — Dump Truck Articulated
Caterpillar 824C — Dozer Wheeled
Caterpillar 825C — Compactor
Caterpillar 826C — Compactor
Caterpillar AD55 — Mining Equipment
Caterpillar D8R II — Tractor Tracked
Caterpillar PM465 — Planer
Driltech D40K — Drilling Equipment
Ford CL-9000 — Truck
Ford CLT-9000 — Truck

Other equipment known to use this engine, via filter-application cross-reference — useful for sourcing parts even when your exact machine isn't listed elsewhere on this page.

Common questions

Which generators use the Caterpillar 3406E / 3456 engine?

The Caterpillar 3406E / 3456 powers 1 generator set(s), including Caterpillar 3456 GENERATOR SET CCB.

What oil filter does the Caterpillar 3406E / 3456 use?

The Caterpillar 3406E / 3456 uses oil filter part numbers Caterpillar 0773673, Caterpillar E38874, Caterpillar 3I1171.

What fuel filter does the Caterpillar 3406E / 3456 use?

The Caterpillar 3406E / 3456 uses fuel filter part numbers Caterpillar 1165436, Caterpillar 2568753, Caterpillar 5134490.