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Caterpillar 3406C Engine

Name: Caterpillar 3406C Engine
Brand: Caterpillar

The Caterpillar 3406C is a 14 L 6-cylinder ta, tta engine rated at 1800 rpm, producing up to 245 kW. It powers generator sets from Caterpillar, including the 3406 and 3406C Industrial Engine. It holds 34 L (9.0 gal) of oil and 34 L (9.0 gal) of coolant.

Also known as: Caterpillar 3406C

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

14.0 L

Displacement

Cylinders

1800 rpm

Rated speed

245 kW

Gross power

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

Service parts for the 3406C

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

Air intake

1 required

612506Air filter$66.97PartsGeek

Oil system

1 required

3890434Oil filter$30.97PartsGeek

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

Engine specifications

Oil capacity	34.0 L
Coolant capacity	34.0 L
Displacement	14.0 L
Cylinders	6
Aspiration	TA, TTA
Rated speed	1800 rpm
Gross power	245 kW

Generator sets powered by this engine

Caterpillar 3406 Caterpillar 3406C Industrial Engine

How to read your Caterpillar engine serial & model number →

Common problems

Fault shutdown 21
Fault alarm 22
Engine overspeed i01226491
Fix: Stop the engine by shutting off the fuel supply to the engine and/or shutting off the air supply to the engine.
SMCS Code: 1000 i01197515
Fix: • Check the crankcase oil level. Maintain the oil level between the “ADD” mark and the “FULL” mark on the oil level gauge. • If necessary, perform minor adjustments. Repair any leaks and tighten any loose bolts. • Note the service hour meter reading. Perform the maintenance that is in the Operation and Maintenance Manual, “Maintenance Interval Schedule”.
Low power or poor performance in the winter i01190421
Fix: Before troubleshooting for low power or for poor performance in the winter, check the type of fuel that is being used. When No. 2 diesel fuel is used the following components provide a means of minimizing problems in cold weather: • Starting aids • Engine oil pan heaters • Engine coolant heaters • Fuel heaters • Fuel line insulation
Low oil pressure or no oil pressure is indicated
Fix: Stop the engine and determine the cause of the problem. Refer to Troubleshooting for further information or consult with your Caterpillar dealer.
High exhaust temperatures Power loss Excessive fan usage Reduction in fuel economy
Cause: Airflow restriction can cause these conditions.
Fix: If an airflow restriction device must be used, the device should have a permanent opening directly in line with the fan hub. The device must have a minimum opening dimension of at least 770 cm2 (120 in2). A centered opening that is directly in line with the fan hub is specified in order to prevent an interrupted airflow on the fan blades. Interrupted airflow on the fan blades could cause a fan failure. Caterpillar recommends a warning device for the inlet manifold temperature and/or the installation of an inlet air temperature gauge. The warning device for the inlet manifold temperature should be set at 65°C (150°F). The inlet manifold air temperature should not exceed 65°C (150°F). Temperatures that exceed this limit can cause power loss and potential engine damage.
Gauge readings that change even if the readings are within specifications
Cause: Significant change in the readings
Fix: Determine the cause of any significant change in the readings, and/or correct the cause of any significant change in the readings. Consult your Caterpillar dealer for assistance.
Engine operating above the normal range and steam becomes apparent.
Fix: 1. Reduce the load and the engine speed (rpm). 2. Inspect the cooling system for leaks. 3. Determine if the engine must be shut down immediately or if the engine can be cooled by reducing the load.
Engine operating above the normal range and steam becomes apparent
Fix: Reduce the load and the engine speed (rpm). Inspect the cooling system for leaks. Determine if the engine must be shut down immediately or if the engine can be cooled by reducing the load.
Decrease in fuel pressure.
Fix: A decrease in fuel pressure usually indicates a plugged fuel filter.
Decrease in fuel pressure
Fix: A decrease in fuel pressure usually indicates a plugged fuel filter.
A lower oil pressure is normal at low idle.
Fix: If the load is stable and the gauge reading changes, perform the following procedure: 1. Remove the load. 2. Reduce engine speed to low idle. 3. Check and maintain the oil level.

Compiled from service & troubleshooting documentation across every generator set that uses the Caterpillar 3406C.

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter	Replace air filter at each oil change and every 250 hours or as needed.		612506	250 hr	Amazon eBay $100.00 PartsGeek $66.97
Fuel filter	Change fuel filter every 1,000 hours or as needed.		—	1000 hr
Oil filter	Replace oil filter at each oil change.		—	250 hr
Battery	Check battery condition every 1,000 hours and replace if necessary.		—	1000 hr
Belt	Inspect belts at each oil change and replace if worn or damaged.		—	250 hr
Coolant	Change coolant at each oil change and every 1,000 hours or as needed.		—	1000 hr
Oil	Change oil and filter every 250 hours or as needed.	34.1	—	250 hr
Spark plug	Replace spark plugs every 2,500 hours or as needed.		—	2500 hr

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

Service intervals

Item	Action	Hours	Months	Notes
Air Tank	Drain	50 hr		Drain water/sediment; every 1900 L (500 gal) fuel or 50 hours
Marine Gear Oil and Filter	Change	50 hr		First service — Change on new or rebuilt marine gears at first 50 hours only, then every 2000 hours thereafter
Zinc Rods	Inspect	50 hr		Every 1900 L (500 gal) of fuel or 50 hours
Clutch Shift Collar and Bearing and Shift Lever	Adjust	125 hr		Every 4750 L (1250 gal) of fuel or 125 hours - lubricate/check/adjust
Aftercooler Core	Clean	250 hr		Clean/Test - Every 9500 L (2500 US gal) of Fuel or 250 Service Hours or Yearly
Alternator and Fan Belts	Replace	250 hr		Inspect/Adjust/Replace - Every 19 000 L (5000 US gal) of Fuel or 250 Service Hours
Alternator and Fan Drive Belts	Inspect	250 hr		Every 12,500 Miles or 250 Service Hours; inspect—adjust if necessary
Batteries	Check	250 hr		Clean/inspect and check electrolyte level
Batteries	Inspect	250 hr		Every 12,500 Miles or 250 Service Hours; inspect electrolyte level
Battery Electrolyte Level	Check	250 hr		Every 19 000 L (5000 US gal) of Fuel or 250 Service Hours
Belts, Hoses and Clamps	Inspect	250 hr
Coolant Conditioner Element	Change	250 hr		Every 12,500 Miles or 250 Service Hours; change element
Cooling System	Clean	250 hr		Every 12,500 Miles or 250 Service Hours; clean radiator fins—inspect hoses
Cooling System	Other	250 hr		Every 12,500 Miles or 250 Service Hours; add conditioner if not equipped with element
Cooling System Coolant Additive Concentration	Test	250 hr		Add liquid coolant additive or replace maintenance element if equipped
Cooling System Coolant Sample (Level 1)	Test	250 hr		Obtain - Every 250 Service Hours
Cooling System Supplemental Coolant Additive (SCA)	Test	250 hr		Test/Add - Every 19 000 L (5000 US gal) of Fuel or 250 Service Hours
Crankcase Breather	Clean	250 hr
Engine Air Cleaners	Clean	250 hr
Engine Air Intake	Clean	250 hr		Every 12,500 Miles or 250 Service Hours; clean oil bath cleaners—clean or replace dry elements
Engine Crankcase	Change	250 hr		Every 12,500 Miles or 250 Service Hours; change oil and filters
Engine Crankcase Breather	Clean	250 hr		Every 19 000 L (5000 US gal) of Fuel or 250 Service Hours
Engine Oil and Filters	Change	250 hr		Every 9500 L (2500 gal) of fuel or 250 hours; standard sump 250 hrs, deep sump 500 hrs
Engine Protective Devices	Check	250 hr		Every 19 000 L (5000 US gal) of Fuel or 250 Service Hours
Engine Valve Lash	Adjust	3000 hr		First service — Inspect/Adjust - First 19 000 L (5000 US gal) of Fuel or 250 Service Hours
Fan Pulley Bearing	Lubricate	250 hr		Every 12,500 Miles or 250 Service Hours; lubricate bearing MPG
Fuel System (drain water/sediment, replace final filter, clean primary filter)	Clean	250 hr		Every 9500 L (2500 gal) of fuel or 250 hours
Magnetic Pickups	Clean	250 hr		First service — Clean/Inspect - First 19 000 L (5000 US gal) of Fuel or 250 Service Hours
Scheduled Oil Sampling (S-O-S)	Test	250 hr		Every 9500 L (2500 gal) of fuel or 250 hours - obtain sample
Engine Breather	Clean	500 hr		Every 25,000 Miles or 500 Service Hours; wash
Fuel Filters	Replace	500 hr		Every 25,000 Miles or 500 Service Hours; replace final fuel filter—clean primary filter
oil	Change	500 hr		3000 Series service intervals increased to 500 hours as standard (3013C, 3024C, 3054, 3056)
Air Fuel Ratio Control	Inspect	1000 hr		Every 50,000 Miles or 1000 Service Hours; inspect for adjustment or repair
Engine Protective Devices	Inspect	1000 hr
Governor	Inspect	1000 hr		Inspect/lubricate linkage; check/adjust fuel ratio control and low idle
Marine Gear	Replace	1000 hr		Every 38000 L (10,000 gal) of fuel or 1000 hours - replace oil and filter, clean strainer/breather, lubricate output shaft seal
Air Compressor	Inspect	2000 hr		Every 100,000 Miles or 2000 Service Hours; inspect—rebuild if necessary
Batteries	Clean	2000 hr		Every 100,000 Miles or 2000 Service Hours; clean battery and electrical connections
Cooling System	Drain	2000 hr		Drain and clean whenever engine overheats or solution is dirty
Cooling System Coolant Sample (Level 2)	Test	2000 hr	12 mo	Obtain - Every 2000 Service Hours or 1 Year

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

Service specifications

Type	Item	Value	Unit	Condition
Clearance	Bearing bracket step minimum	less than 0.0762	mm
Clearance	Exhaust valve lift during engine brake operation	.070	in
Clearance	Magnetic Pickup Back-off from Flywheel Ring Gear	180 +/- 15	degrees (1-1/2 turn CCW)
Clearance	Master piston stroke (Caterpillar)	.400	in
Clearance	Oil supply adapter gap to rocker arm pedestal	.020	in	approximately, to avoid bending adapter
Clearance	Pedestal height difference limit (engines prior to 7FB-39279)	.005	in	if more than .005 difference, machine higher pedestal or shim
Clearance	Slave piston to crosshead clearance (*460 HP)	.090	in	gauge P18488
Clearance	Slave piston to crosshead clearance (3406 B+C 1991 to present)	.070	in	gauge P13184
Clearance	Slave piston to crosshead clearance (3406)	.060	in	gauge P7446
Clearance	Slave piston to crosshead clearance (3406B prior 1991)	.080	in	gauge P34670
Clearance	Turbocharger Shaft End Play	0.076 to 0.203	mm (0.003 to 0.008 in)
Clearance	Turbocharger end play	.003 inch (0.07 mm) to .008 inch (0.203 mm)		checked with a dial indicator
Gap	Fan/alternator belt deflection	2 inch (1 cm)		with 25 lb. (110 N) force midway between the pulleys
Other	Belt tension deflection	0.50 to 0.75	inch	110 N (25 lb) force midway between pulleys
Other	Belt tension deflection	13 to 19	mm	110 N (25 lb) force midway between pulleys
Other	Coolant fill rate	5 U.S. gallons (19 liters) per minute or less		to help avoid air locks
Other	Coolant level below filler pipe bottom	13	mm
Other	Cooling system conditioner concentration	new or reconditioned engine: 3% to 6% concentration; add 1 pint (.50 liters) for each 4 gal. (15.14 liters) of coolant to obtain 3% concentration. Thereafter: add 1 pint (.50 liters) for each 16 gal. (60.50 liters) of coolant to maintain 3% concentration.
Other	Cooling system fill rate (maximum)	19	L per minute	to avoid air locks
Other	Engine oil supplemental filtration	12 qt. supplemental oil filtration system extends the normal interval for CD oils to 16,500 miles
Other	Engine valve rotator operation	should turn slightly when valves close
Other	Exhaust valve operation rate by engine brake	17.5	times per second
Other	Generator excitation PMG short circuit capability	3 X In for 10 seconds
Other	Glow plug current draw	12.5 amperes each; 75 amps total		12 volt; six glow plugs
Other	High idle speed for droop governors	approximately 2% to 5%	above full load speed	governors equipped with droop
Other	Rating condition (diesel 7 L and higher)	99 kPa (29.31 in Hg) dry barometer, 25°C (77°F)		SAE J1995 inlet air standard
Other	Rating condition (diesel up to 6.6 L)	100 kPa (29.5 in Hg) total barometric pressure, 1 kPa (.295 in Hg) vapor pressure, 25°C (77°F)		ISO/TR14396 inlet air standard
Other	Rating condition (gas)	100 kPa (29.61 in Hg) and 25°C (77°F)		SAE J1349 standard
Other	Speed droop values commonly used	3% and 0%	%
Other	Vibration damper inspection	dented, cracked, leaking, bent or discolored damper must be replaced
Other	Voltage droop for 0.8 power factor load	approximately 5	%	loads with a power factor of 0.8
Pressure	Air Cleaner Maximum Pressure Differential	7.5	kPa (30 in water / 1.1 psi)
Pressure	Air cleaner cleaning pressure air	30 psi (205 kPa) maximum		pressure air cleaning
Pressure	Air cleaner cleaning water pressure	40 psi (280 kPa) maximum		water cleaning
Pressure	Coolant system pressure test - use 9S-8140 Pressurizing Pump	9S-8140
Pressure	Engine oil pressure at low idle	186 to 344	kPa	low idle speed
Pressure	Fuel pressure (below which engine will not operate properly)	160	kPa
Pressure	Maximum air pressure for cleaning	205	kPa	deadheaded nozzle with chip guarding
Pressure	Maximum water pressure for cleaning	275	kPa
Pressure	Minimum recommended oil pressure	103	kPa	600 rpm
Pressure	Minimum recommended oil pressure	15	psi	600 rpm
Pressure	Normal operating engine oil pressure	275 to 600	kPa	engine running at rated engine speed, SAE 10W30 oil, operating oil temperature 104 C (219.2 F), normal engine water temperature
Pressure	Primary filter/water separator change pressure	50 to 70	kPa	15 to 20 inches Hg
Pressure	Typical engine oil pressure at rated rpm with SAE10W30 (turbocharged)	275 to 606	kPa	rated rpm
Pressure	Typical engine oil pressure at rated rpm with SAE10W30 (turbocharged)	40 to 88	psi	rated rpm
Pressure	Unit injector fuel injection pressure	1240	bar (18 000 psi)
Resistance	Exciter Armature (Rotor) (L2) resistance	less than 0.1	ohm	room temperature
Resistance	Exciter Field (Stator) (L1) resistance	3.0 to 6.0	ohms	room temperature
Resistance	Insulation resistance minimum (contaminated generator)	1	megohm
Resistance	Main Armature (Stator) (L4) resistance	less than 0.1	ohm	room temperature
Resistance	Main Field (Rotor) (L3) resistance	0.75 to 2.0	ohms	room temperature
Resistance	Pilot Exciter Armature (L5) resistance	less than 0.1	ohm	room temperature
Resistance	Varistor (CR7) resistance	minimum 15000	ohms
Speed	Actual RPM of overspeed (1500 full load rpm)	1770	rpm	multiply full load RPM by 1.18
Speed	Actual RPM of overspeed (1800 full load rpm)	2124	rpm	multiply full load RPM by 1.18
Speed	Engine brake design speed	2100	RPM	designed to run and give maximum performance
Speed	Frequency vs RPM - four-pole generator	divide the RPM by 30	Hz
Speed	Frequency vs RPM - six pole generator	divide the RPM by 20	Hz
Speed	Generator set functional test minimum phase voltage	85	VAC	half rated speed
Speed	Low idle (50 Hz units)	80	percent of full load speed

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

Recommended fluids

Fluid	Grade	Standard	Ambient	Capacity	Notes
Coolant	Cat DEAC				Diesel; 3,000 Service Hours or Three Years; annual S·O·SSM Level 2 coolant sampling and analysis
Coolant	Cat DEAC Diesel Engine Antifreeze/Coolant	ASTM D4985 or ASTM D5345		58.0 L	Acceptable; 1:1 mixture of water and glycol; service life three years; does not require SCA at initial fill
Coolant	Cat ELC				Diesel; 12,000 Service Hours or Six Years; add Cat ELC Extender at 6,000 service hours or one half of service life; annual S·O·SSM Level 2 coolant sampling and analysis
Coolant	Cat ELC Extended Life Coolant	Caterpillar EC-1		58.0 L	Preferred; 1:1 mixture of water and glycol; service life six years; add ELC Extender once
Coolant	Cat NGEC				Natural Gas; 16,000 Service Hours or Three Years; use interval that occurs first
Coolant	Caterpillar Antifreeze / liquid Cooling System Additive (Conditioner)				Maintain within 13 mm (1/2 in) below bottom of fill pipe; add 0.24 L (1/4 US pint) additive per 30 L (8 U.S. gal) capacity; concentration 3-6% (up to 8% for water+SCA)
Coolant	Caterpillar Cooling System Conditioner liquid or coolant conditioner element; ethylene glycol antifreeze solution; Dowtherm 209 Full-Fill coolant				Never use both the liquid cooling system conditioner and the coolant conditioner element at the same time. Do not use Caterpillar Cooling System Conditioner or Coolant Conditioner Elements with Dowtherm 209 Full-Fill coolant.
Coolant	Caterpillar SCA and Water				For stationary applications not requiring boiling/freezing protection; minimum six percent to maximum eight percent SCA concentration; service life two years
Engine oil	CD engine oil	If fuel has over 0.5% sulfur content, CD engine oil must have a TBN of 20 times the percentage of fuel sulfur (TBN as measured by ASTM D-2896 method).			A 12 qt. supplemental oil filtration system extends the normal oil and filter change interval to 16,500 miles.
Engine oil	Cat NGEO				Natural Gas
Engine oil	SAE 10W30				Referenced as the oil used when normal operating engine oil pressure is specified
Engine oil	low sulfated ash oil				Required for U.S. EPA Tier 4 Final, EU Stage IV engines.
Engine oil	Cat Arctic DEO SYN SAE 0W-30		-40°C to 30°C		Engine Crankcase; Industrial Engines
Engine oil	SAE 0W-20	Cat DEO Multigrade API CH-4/API CG-4	-40°C to 10°C
Engine oil	SAE 0W-30	Cat DEO Multigrade API CH-4/API CG-4	-40°C to 30°C
Engine oil	SAE 0W-40	Cat DEO Multigrade API CH-4/API CG-4	-40°C to 40°C
Engine oil	Cat DEO SYN SAE 5W-40		-30°C to 50°C		Engine Crankcase; Industrial Engines
Engine oil	SAE 5W-30	Cat DEO Multigrade API CH-4/API CG-4	-30°C to 30°C
Engine oil	SAE 5W-40	Cat DEO Multigrade API CH-4/API CG-4	-30°C to 50°C
Engine oil	Cat DEO SAE 10W-30		-18°C to 40°C		Engine Crankcase; Industrial Engines
Engine oil	SAE 10W-30	Cat DEO Multigrade API CH-4/API CG-4	-18°C to 40°C
Engine oil	Cat DEO SAE 15W-40		-9°C to 50°C		Engine Crankcase; Industrial Engines
Engine oil	SAE 15W-40	Cat DEO Multigrade API CH-4/API CG-4	-9°C to 50°C
Fuel		Ultra Low Sulfur Diesel (ULSD)			Contains less than or equal to 15 parts per million sulfur (mg/kg); required for U.S. EPA Tier 4 Final, EU Stage IV engines. B20 biodiesel capability available.
Fuel	35° API gravity at 60°F (16°C)	LHV 18,390 Btu/lb (42 780 kJ/kg)			Fuel at 85°F (29°C) weighing 7.001 lbs/U.S. gal (838.9 g/liter)
Fuel	No. 1-D or No. 2-D	ASTM D975			Use No. 1 diesel fuel or a blend of No. 1 and No. 2 for cold-weather operation; No. 2 is most commonly used
Fuel	No. 2 fuel				3600 engines designed for 80 000 hours on No. 2 fuel; ratings based on API gravity of 35 at 15 C (60 F), LHV of 42 780 kJ/kg used at 29 C (84 F) with a density of 838.9 g/L
Fuel	clean diesel fuel				Lubricate the new final fuel filter gasket with clean diesel fuel.
Grease	Cat Generator Set Grease				Part Number 108-8611
Grease	High Speed Ball Bearing Grease				Fan drive bearing grease fitting

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

Procedures

Adjust Engine Valve Lash adjustment

⚠ Valves must be fully closed.

Tools: Caterpillar Part Number 9S9082 engine turning tool, feeler gauge

Adjust valves with the engine stopped and cold.
Remove the flywheel housing timing hole cover.
Remove the plug.
Rotate the flywheel in direction of engine rotation until timing bolt can be installed in flywheel.
Install the timing bolt in the flywheel. This is the top bolt of the two bolts that secure the flywheel housing cover.
Determine if No. 1 piston is on compression or exhaust stroke. The cylinder on compression will have both inlet and exhaust valves closed. If valves are open, rotate engine 360° to obtain TDC No. 1 co
With No. 1 piston at TDC on compression, check lash between the bridge and rocker arm on exhaust valves of cylinders 1, 3 and 5, and inlet valves for cylinders 1, 2 and 4.
To adjust, loosen valve adjusting lock nut and turn adjusting screw to allow proper size feeler gauge to pass between top of bridge and the valve rocker arm.
Set lash at .015 (0.38 mm) for inlet valves and .030 (0.76 mm) for exhaust valves.
Tighten adjusting screw locknut and check lash.
Turn flywheel 360° in direction of engine rotation. Align flywheel timing bolt with the timing hole in the flywheel. No. 6 cylinder will be at TDC compression stroke.
Check lash between the bridge and rocker arm on exhaust valves for cylinders 2, 4 and 6, and inlet valves for cylinders 3, 5 and 6. Adjust valves if necessary.

Adjust Valve Bridge adjustment

⚠ Valves must be fully closed.

Valves must be fully closed.
If bridge was removed, put engine oil on the bridge dowel in the cylinder head and in the bore in the bridge.
Install the bridge with the adjustment screw toward the exhaust manifold.
Back off adjusting screw several turns (counterclockwise), making sure it is not in contact with the valve stem.
Firmly press straight down on the rocker arm above point of contact with bridge.
Turn the adjusting screw clockwise until contact is made with the valve stem. Turn the adjusting screw an additional 30° (one-twelfth turn).
Hold the adjusting screw in this position and tighten the locknut to 22 + 3 lb. ft. (80 = 4 Nm).
Put engine oil at the point where the rocker arm makes contact with the bridge.
After checking the bridge adjustment, make the valve lash adjustment.

Dipstick Calibration adjustment

Drain crankcase and install new filters after normal operating temperature reached
Tighten crankcase drain plug to 70+/-14 N-m (50+/-10 lb ft)
Add oil per Refill Capacities chart and allow 5 minutes to drain into sump
Crank engine with filters installed before starting to avoid bearing damage
Start and run engine to circulate oil and fill filters
Stop engine, wait 5 minutes, mark ADD level on dipstick if different from actual
Add specified additional oil quantity (shallow: 3.8 L / deep: 8 L) and mark FULL level
Restart, run to operating temperature at LOW IDLE, mark opposite side FULL for warm/idle reading

Engine Valve Lash - Inspect/Adjust adjustment

⚠ Hot engine components can cause burns.

⚠ Only qualified service personnel should perform this maintenance.

Ensure the engine cannot be started; do not use the starting motor to turn the flywheel.
Ensure the engine is stopped and allow valves to cool.
Refer to the Systems Operation/Testing and Adjusting Manual for the complete procedure.
Set inlet valve lash to 0.38 mm (0.0150 inch).
Set exhaust valve lash to 0.76 mm (0.030 inch).
Perform initial adjustment at the first scheduled oil change.

Engine Valve Lash Check/Adjust adjustment

⚠ Do not use starting motor to turn flywheel; hot components can burn

Disable starting motors so engine cannot start during procedure
Allow at least 20 minutes for valves to cool to block/head temperature
Clean area around valve mechanism covers before removal
Adjust valve bridges before adjusting any valves, per cylinder
Check/adjust valve lash to nominal value in Valve Lash Setting chart
Start engine at LOW IDLE and observe valve rotator rotation after setting lash

Overhead Adjustments adjustment

⚠ Eye protection must be worn when using air pressure.

⚠ The studs do not provide housing alignment; the locating pin must be fitted.

Tools: air pressure (blow gun), 9/16 crowfoot wrench, torque wrench

Apply clean oil to the crosshead bore, install on the engine and adjust according to the Caterpillar manual.
Check clearance between the underside of the crosshead on the adjusting screw side and the top of the valve rotocoil.
Remove the front dowel pin; lubricate and install the Pacbrake oil supply adapter leaving about .020 gap at the pedestal.
Remove the rear locating pin and replace it with the longer Pacbrake pin, rounded end up, driven until it stops.
Using air pressure, remove oil trapped in the holddown bolt holes; wear eye protection.
Re-install the front rocker assembly, ensuring the push-tubes are in place.
Install the two Pacbrake studs with Pacbrake washers in the outside locations; reuse the Caterpillar bolt and washer in the center.
Apply 6V4876 molykote paste on the threads and between the washer and the underside of the bolt head and stud hex.
Torque the bolts and studs to 200 lb.ft. (270 N.m), then to 330 lb.ft. (450 N.m) in 50 lb. (70 N.m) increments.
Repeat steps on the rear.
Remove Cat head bolts on the front of the engine, blow out oil, and lubricate the threads and bearing surfaces.
Install the Pacbrake support base reusing the Cat head bolts and washers and torque to 330 lb.ft. (450 N.m).
Install the housing support studs into the support bases (hex nut end into base) and torque to 50 lb.ft. (70 N.m) using a 9/16 crowfoot wrench.
Install the 7/16 NF nuts and washers and run the nuts to the bottom of the threads.
Repeat steps on the rear.

Slave Piston Adjustment Procedure adjustment

Tools: Pacbrake feeler gauge (P7446, P34670, P13184 or P18488), torque wrench

Perform at any location where the exhaust crosshead is loose to the touch (no pressure from a rocker arm).
Insert a Pacbrake feeler gauge between the slave piston feet and the crosshead.
Turn the Paclash adjusting screw down until a slight drag is felt on the feeler gauge.
Torque the lock-nut to 25 lb.ft. (35 N.m) and re-check the clearance.

VR3 Regulator Adjustment Procedure adjustment

⚠ The VR3 regulator is protected by a fuse(s) and a solid-state overcurrent protection. If a fuse becomes open, contact a Caterpillar dealer.

Remove the access panel of the generator.
Loosen the locknut on the voltage droop potentiometer (1).
Remove the protective screw from the voltage level potentiometer (2) and from the voltage gain potentiometer (3).
Turn the voltage droop potentiometer (1) counterclockwise to zero droop. Tighten the locknut.
Turn the voltage gain potentiometer (3) counterclockwise to zero, then to about 1/4 of full range of clockwise travel.
Perform required maintenance on the engine before you start the engine.
Start the engine and allow the engine to warm up.
Increase engine speed to full governed rated speed (high idle).
Set the no-load voltage with the voltage level potentiometer (2) or the voltage adjust rheostat.
Close the load circuit breaker and apply full load gradually. Adjust governor control to nameplate frequency or rated speed.
If the voltmeter reading increases above no-load voltage, turn the voltage gain potentiometer counterclockwise. If it decreases, turn it clockwise.
Remove the load. If necessary, adjust the voltage level potentiometer (2) to obtain desired voltage.
Apply the load. Repeat Steps 10 through 12 until the voltage at no load equals the voltage at full load.
Tighten the locknuts. Install the protective screws and the access panel of the generator.

Check Glow Plugs diagnostic

Tools: ammeter with capacity over 75 amps

Disconnect the wire lead from the glow plug terminal on the HEAT-START switch.
Install an ammeter with a capacity of over 75 amps, in series, between the disconnected lead and the terminal on the HEAT-START switch.
Turn HEAT-START switch to HEAT.
Observe the ammeter. Each 12 volt glow plug draws approximately 12.5 amperes. The ampere draw of one glow plug multiplied by 6 will be 75 amps, the total ampere draw of the glow plugs in the engine. A
If a defective glow plug is indicated, disconnect one glow plug lead at a time.
Turn switch to the HEAT position. Observe the ammeter. Reconnect the lead.
The glow plug that does not change the reading on the ammeter, when the switch is turned on, is the defective glow plug.

Generator Set Functional Test diagnostic

⚠ Do not operate the generator set at a speed higher than one-half of the rated speed.

Tools: 6V-7070 Digital Multimeter, 12 VDC battery, Potential Transformer

Stop the generator. Connect the potential transformer's high voltage winding to generator terminals T1 and T2. Connect the voltmeter to the low voltage winding.
Disconnect wires F1+ and F2- from the voltage regulator. Disconnect the generator from the load.
Connect a 12 VDC automotive battery to wires F1+ and F2-.
Operate the generator set at half the rated speed.
Measure the AC voltage across the low voltage terminals corresponding to T1-T2, T2-T3, and T3-T1. Record the voltages.
Monitor the voltage between any two locations, then decrease the generator set speed by 10 percent and increase it by 10 percent.
The measured voltages should be nearly equal and should measure a minimum of 85 VAC.
When speed is decreased by 10 percent the voltages should decrease by 10 percent; when increased by 10 percent the voltages should increase by 10 percent.

Rotating Rectifier - Test diagnostic

Tools: 6V-7070 Digital Multimeter, 146-4080 Digital Multimeter (RS-232)

Touch the red ohmmeter lead to the rectifier terminal marked '+'.
Touch the black ohmmeter lead to terminals AC1, AC2, and AC3; the meter should indicate an open circuit or high resistance.
Touch the black ohmmeter lead to the rectifier terminal marked '+'.
Touch the red ohmmeter lead to terminals AC1, AC2, and AC3; the meter should indicate a good diode or low resistance.
Touch the black ohmmeter lead to the rectifier terminal marked '-'.
Touch the red ohmmeter lead to terminals AC1, AC2, and AC3; the meter should indicate an open circuit or high resistance.
Touch the red ohmmeter lead to the rectifier terminal marked '-'.
Touch the black ohmmeter lead to terminals AC1, AC2, and AC3; the meter should indicate a good diode or low resistance.
If the meter does not indicate the expected result, the rectifier is bad. Replace the rectifier.

Rotating Rectifier - Test (Brushless Exciter) diagnostic

Tools: 6V-7070 Digital Multimeter, 9U-7330 Multimeter, 146-4080 Digital Multimeter (RS-232), 7X-1710 Multimeter Probe Group

Remove the cover from the exciter.
Remove the nut securing the rectifier to the heat sink.
Remove the diode lead and lift the rectifier from the heat sink.
Connect ohmmeter leads across the rectifier and note reading.
Reverse the ohmmeter leads and note reading.
Low resistance one direction and high the other indicates a good rectifier.
Low resistance both directions indicates shorted rectifier.
High resistance both directions indicates open rectifier; replace faulty rectifiers.

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

Voltage reconnection

Voltage	Phase	Connection	Leads	Notes
	3	Delta - 6 lead	6	Winding pitch must be two-thirds or the generator must be derated.
	3	Wye - 10 lead (high voltage)	10	Illustration 13. Only used on 3306B generator sets and 3406C generator sets. Terminal T0 is the neutral lead.
	3	Wye - 10 lead (low voltage)	10	Only used on 3306B and 3406C generator sets. Terminal T0 is the neutral lead.
	3	Wye - 12 lead (high voltage)	12	Terminals T10, T11, and T12 become neutral connections when tied together.
	3	Wye - 12 lead (low voltage)	12	Terminals T10, T11, and T12 become neutral connections when tied together.
	3	Wye - 4 lead	4	Only used on 3306B generator sets and 3406C generator sets. Terminal T0 is the neutral lead.
	3	Wye - 6 lead	6	Terminals T4, T5, and T6 become neutral connections when the terminals are tied together.
	three-phase	10 Lead Wye Configuration - High Voltage	Terminal T0 is the neutral lead	For 3306B and 3406C generator sets only
	three-phase	10 Lead Wye Configuration - Low Voltage	Terminal T0 is the neutral lead	For 3306B and 3406C generator sets only
	three-phase	12 Lead Delta Configuration	Terminals T6 and T9 become the neutral connection when tied together and grounded; T2 and T10 connection is the high phase
	three-phase	12 Lead Wye Configuration - High Voltage	Terminals T10, T11 and T12 become neutral connection when tied together
	three-phase	12 Lead Wye Configuration - Low Voltage	Terminals T10, T11 and T12 become neutral connection when tied together
	three-phase	4 Lead Wye Configuration	Terminal T0 is the neutral lead	For 3306B and 3406C generator sets only
	three-phase	6 Lead Delta Configuration
	three-phase	6 Lead Wye Configuration	Terminals T4, T5 and T6 become neutral connection when tied together
240	3	Delta - 12 lead	12	Terminals T6 and T9 become the neutral connections when tied together and grounded. T2 and T10 connection is the high phase. 240 V, 60 Hz, three-phase: 208 Volts between the high phase and neutral; 240 Volts between either of the low phases and neutral.
240	three-phase	Delta Configuration (60 Hz, 12 Lead)	T6 and T9 neutral when tied together and grounded	208 Volts between high phase and neutral; 240 Volts between either low phase and neutral
480	three-phase	Wye Configuration (typical series Wye, 60 Hz, 12 Lead)	T10, T11, T12 neutral when tied	For 3406E, 3412C and 3500 series generator sets only - high voltage

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 3406C family

228

Part #	Description	Category
102-9720	Cleaning Kit (detergent and oil for AIRSEP air cleaner elements)	air_filter
1W7411	CLEANER GP-AIR(D)(HEAVY DUTY)	air_filter
4N0015	Air filter outer	air_filter
6I2504	Air filter inner	air_filter
8N9759	MOUNTING GP - AIR CLEANER	air_filter
50-amp	Alternator	alternator
6N9294	CHARGING ALTERNATOR 24V 35 AMP	alternator
118-2018	V-belt	belt
164-4599	V-belt	belt
1W4878	BELT GUARD - ALTERNATOR PULLEY	belt
4N6302	V-belt	belt
6N6798	V-belt	belt
W200-1002	Buffer Seal	buffer_seal
9N2366	Precharge filter element (attachment coolant conditioner group maintenance filter element)	coolant_filter
9N3368	Coolant Conditioner Element	coolant_filter
i01329129	Coolant	coolant_filter
i01359892	Coolant	coolant_filter
W200-1001	Cylinder Rod Seal - Wiper Seal	cylinder_rod_seal
4C4611	Cooling System Cleaner, Fast Acting-Type, 3.8 L (1 U.S. gal) container	fluid
6V4511	Cooling System Cleaner, Standard-Type, 1.9 L (1/2 U.S. gal) container	fluid
ON5561	Silicone Lubricant for battery cable clamps and terminals	fluid
1R-0749	Fuel Secondary - ADV	fuel_filter
1R-0750	High Efficiency Fuel Filter	fuel_filter
1R-0751	High Efficiency Fuel Filter	fuel_filter
1R-0755	High Efficiency Fuel Filter	fuel_filter
1R-0756	High Efficiency Fuel Filter	fuel_filter
1R-0766	High Efficiency Fuel Filter	fuel_filter
326-1642	Filter water separator	fuel_filter
326-1643	Filter water separator	fuel_filter
3S3875	Filter fuel	fuel_filter
9N3717	Filter water separator	fuel_filter
1282922CAT	Water Pump Gasket Set - 0.4 lbs/ 0.18 kgs, 5" Length, 27mm Width, 27mm Depth, 11 Application: 3400	gasket
13373	Gasket, lens oval	gasket
1555619CAT	Flywheel Housing Gasket - 3406	gasket
1609874CAT	Single Cylinder Liner Gasket Set - 3406/ 3412 0.1 lbs/ 0.04 kgs	gasket
2161252CAT	Single Cylinder Head Gasket Set - 3406/ 3406E	gasket
3N4861	GASKET	gasket
4N1151	Gasket oil pan	gasket
6I3066	Gasket cylinder head	gasket
DM-3E3322	GASKET SET, FUEL SYSTEM 3406	gasket
DM-3E7474	GASKET SET, FUEL SYSTEM 3406	gasket
DM-3E7485	GASKET SET, FUEL SYSTEM 3406	gasket
DM-3E7495	GASKET SET, FUEL SYSTEM 3406	gasket
DM-6I3066	GASKET, CYL. HD. 3406	gasket
DM-8C4452	GASKET SET, FUEL SYSTEM 3406	gasket
DM-8C6538	GASKET SET, FUEL SYSTEM 3406	gasket
DM-8C6772	GASKET SET, FUEL SYSTEM 3406	gasket
DM-8C8490	GASKET SET, FUEL SYSTEM 3406	gasket
DM-8C8764	GASKET SET, FUEL SYSTEM 3406	gasket
M-1282922	Water Pump Mounting Gasket	gasket
M-1609874	Gasket Set - Cylinder Liner Packing	gasket
M-1P436	1 Fuel Priming Pump Gasket	gasket
M-3639022	Gasket Set - Front Structure	gasket
M-4N1151	Oil Pan Gasket	gasket
M-4N1151-6	Oil Pan Gasket	gasket
M-4N1156	Gasket	gasket
M-4N7253	Nozzle Adapter Gasket	gasket
M-5P5678-6	Valve Cover Gasket	gasket
M-5P5678-9	Valve Cover Gasket	gasket
M-7C307	Gasket	gasket
MCB3406031	Overhaul Gasket Set	gasket
MCB3406032	In-Chassis Gasket Set	gasket
MCB3406033	Cylinder Head Set	gasket
3T8705	Glow plug	glow_plug
3T8706	Glow plug	glow_plug
i01206414	Standard Torque for Constant Torque Hose Clamps	hose
i01206505	Standard Torque for Worm Drive Band Hose Clamps	hose
094-4412	Filter hydraulic	hydraulic_filter
W200-1000	Hydraulic Cylinder Reseal Service Kit	hydraulic_filter
3N4859	IMPELLER	impeller
M-1007551	Fuel Nozzle - 7000 Series	injector
M-1007556	Fuel Nozzle - 7000 Series	injector
M-1007557	Fuel Nozzle - 7000 Series	injector
M-1007558	Fuel Nozzle - 7000 Series	injector
M-1279792	Fuel Nozzle - 7000 Series	injector
M-1279793	Fuel Nozzle - 7000 Series	injector
M-1311243	Fuel Nozzle - 7000 Series	injector
M-4W7017	Fuel Nozzle - 7000 Series	injector
M-4W7018	Fuel Nozzle - 7000 Series	injector
M-4W7022	Fuel Nozzle - 7000 Series	injector
M-7W7026	Fuel Nozzle - 7000 Series	injector
M-7W7032	Fuel Nozzle - 7000 Series	injector
M-7W7037	Fuel Nozzle - 7000 Series	injector
M-7W7040	Fuel Nozzle - 7000 Series	injector
M-7W7041	Fuel Nozzle - 7000 Series	injector
M-7W7042	Fuel Nozzle - 7000 Series	injector
M-7W7043	Fuel Nozzle - 7000 Series	injector
M-7W7044	Fuel Nozzle - 7000 Series	injector
M-9L6884	Fuel Nozzle - Capsule	injector
M-9N3246	Fuel Nozzle - Capsule	injector
102-2828	Filter oil	oil_filter
1R1808	Filter oil	oil_filter
9M9740	Filter oil	oil_filter
0P8708	POWER PLUS RENTL FINANCE PRGM	other_service
0P9484	0P948401JUL98PRC PROPGM641-6	other_service
102-9721	Air/Vacuum Limiter Filter Element Cleaning Kit (non-U.S.)	other_service
1031956	MOUNTING GP - CONTACTOR	other_service
1036101	CONTROL GP -A	other_service
1037284	MOUNTING GP - BREAKER	other_service
1047942	FASTENER GP	other_service
1048615	BASE GP - FUEL TANK &	other_service
1059710	LINES GP - OIL DRAIN	other_service
1069931	LINES GP - DRAIN	other_service
1080723	HARNESS GP - WIRING	other_service
1095264	PANEL AR - CONTROL	other_service
1114219	MOUNTING GP - CONTROL PANEL	other_service
1114421	ACTUATOR AS - 524 GOVERNOR	other_service
1117534	MOUNTING GP - ACTUATOR	other_service
1172855	TRANSFER GP	other_service
1309415	3406 DITA/XQ350 RENTAL PKG	other_service
1315455	CONTROL AS	other_service
1315544	RADIATOR GP	other_service
1N3876	3406 DITA ENGINE AR - BASIC	other_service
249-0433	Oxidation Catalyst Assembly - Round	other_service
256-0326	Oxidation Catalyst Assembly - Round	other_service
2T8141	387 KW @ 1800 RPM (519 BHP)	other_service
2W8198	SOLENOID SHUTOFF - ETR 24 V	other_service
3N4858	SHAFT	other_service
3N4860	CAM LINER	other_service
3N4862	WEAR PLATE	other_service
4N3093	BLOWER FAN	other_service
4N6540	MOUNTING GP-HEATER	other_service
4N9778	UPPER RADIATOR CONNECTIONS	other_service
4P3359	COUPLING	other_service
4P6247	PICK UP GP - MAGNETIC	other_service
4P7610	PICK UP GP - MAGNETIC	other_service
4P9687	SR4 GENERATOR AR-POWER (60HZ)	other_service
4W1727	COVER GP	other_service
4W5828	AIR INLET HOOD	other_service
5P2506	LITERATURE GP - ENGLISH	other_service
5P2586	OIL - BULK - ONE LITER	other_service
6I0371	ENCLOSURE GP	other_service
6L2927	DRY ELBOW	other_service
6N8878	FUEL PRESSURE GAUGE	other_service
6V4876	Molykote paste	other_service
7E5996	Connecting rod	other_service
7E6247	JACKET WATER HEATER	other_service
7N8840	FAN DRIVE 0.800 RATIO	other_service
7W1340	MOUNTING GP - ALTERNATOR	other_service
8N1726	Connecting rod	other_service
9G4231	BATTERY - 12 VOLT	other_service
BER0005	BEARING	other_service
CAMSET0018	CAM LINER	other_service
DZ111166	(3402) (3404) (3408) (3409) (974G)	other_service
JSK002601	SERVICE KIT	other_service
M-2485513	1 Regulator - 180ºC	other_service
P34605	Housing Assembly Group Front (distributor body marked FRONT)	other_service
P34610	Housing Assembly Group Rear (distributor body marked REAR)	other_service
P34616	P-36 Basic Kit	other_service
P34617	Electrical Group - Mechanical (Harness P813-CT included)	other_service
PEHP3036	Cat Reman Short and Long Blocks	other_service
PEHP3036-01	Cat Reman Short and Long Blocks	other_service
QEHQ9870	Rear Wheel Assist System	other_service
SHA0046	SHAFT	other_service
WER0010	WEAR PLATE	other_service
g00104545	Illustration 4	other_service
g00107406	Illustration 1: Safety message for the clutch located on the clutch housing (if equipped).	other_service
g00107407	Illustration 2: Safety message for rotating gears that can cause entanglement of the fingers and hands.	other_service
g00291056	Illustration 20 (Electronic Overspeed Switch with Cranking Termination)	other_service
g00293335	Illustration 19 (Magnetic pickup, Flywheel housing)	other_service
g00367054	The warning label for lifting the engine with a fuel tank is located on the fuel tank (if equipped).	other_service
g00455028	Improper jumper cable connections can cause an explosion resulting in personal injury.	other_service
g00524010	Typical location of the batteries in the battery compartment	other_service
g00524148	Lift eyes or tank can fail when lifting tank containing fluids resulting in possible personal injury. Drain tank of all fluids before lifting.	other_service
g00687600	Always use a board or cardboard when you check for a leak. Leaking fluid that is under pressure can penetrate body tissue.	other_service
g00702020	Wear a hard hat, protective glasses, and other protective equipment, as required.	other_service
g00702022	Caterpillar equipment and replacement parts that are shipped from Caterpillar are asbestos free.	other_service
g00704000	Illustration 8	other_service
g00706404	Illustration 7	other_service
g00722253	Illustration 12	other_service
i00061495	Information Plate	other_service
i00062369	Engine Stopping	other_service
i00610276	Reference Numbers	other_service
i00621349	Standard Torque for Inch Fasteners	other_service
i00621350	Standard Torque for Metric Fasteners	other_service
i00777190	Drain tank of all fluids before lifting.	other_service
i00826199	Engine Identification	other_service
i01072501	Before Starting Engine	other_service
i01103904	Engine Starting	other_service
i01193826	Emissions Certification Film	other_service
i01359622	Mounting and Dismounting	other_service
i01359666	Crushing Prevention and Cutting Prevention	other_service
i01359759	General Hazard Information	other_service
i01368857	Safety Signs and Labels	other_service
i01369271	Model View Illustrations	other_service
i01369284	Engine Description	other_service
i01369380	Serial Number Plate	other_service
i01369505	Gauges and Indicators	other_service
i01369587	Engine Features and Controls	other_service
108-6633	Fuel pump	pump
1313533	PUMP GP - GOVERNOR	pump
135-4925	Water pump	pump
138-6744	Water pump repair kit	pump
161-4111	Oil pump	pump
1W1700	Lift/transfer pump	pump
384-8612	Lift/transfer pump	pump
5N4852	PUMP ASSY	pump
JPR-CT3406	PUMP ASSY	pump
M-1052508	1 Fuel Priming Pump	pump
M-1354926	Water Pump	pump
M-1375541	Fuel Priming Pump	pump
M-1W1700	Fuel Transfer Pump	pump
M-4N733	Oil Pump	pump
142-5867	Front seal	seal
142-5868	Rear seal	seal
3N4863	OIL SEAL	seal
3N5632	M-SEAL	seal
4W3864	Water pump seal	seal
M-1090077	Seal O-Ring	seal
M-1425867	Front Crankshaft Seal	seal
M-1425868	Rear Crankshaft Seal	seal
M-1632478	6 6 Valve Stem Seal - Exhaust	seal
M-2S2251	Nozzle Adapter Seal Ring	seal
M-3S9643	Regulator Seal	seal
M-5H7153	Nozzle Adapter Seal Ring	seal
M-5S2106	Fan Hub Seal	seal
M-7F2122	Fan Hub O-Ring Seal	seal
M-8M5249	Nozzle Adapter Seal Ring	seal
MCBKT7000	Nozzle Seal Kit - 7000 Series	seal
MCSSET0007	M-SEAL(WITH SNAP-RING)	seal
ESD5526	Speed Controller	speed_controller
4N1062	ELECTRIC STARTING MOTOR LH 24V	starter
247-7133	Thermostat	thermostat
248-5513	Thermostat	thermostat
M-1209453	Regulator - 170°	thermostat
M-2477133	Regulator - 190°	thermostat
7C7691	Turbocharger	turbocharger
W200-1003	U-cup Seal	u_cup_seal

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

Aftermarket parts that fit this engine

2H-3750 FridayParts $598.56 5F-4899 FridayParts $598.56 12.7mm FridayParts $121.08 3N-7758 FridayParts $121.08 218-9901 FridayParts $88.10 107-4402 FridayParts $39.99 3E-6466 FridayParts $73.99 162-2073 FridayParts $73.99 147-7975 FridayParts $217.50 5P-8309 FridayParts $48.90 100-7567 FridayParts $430.99 127-9793 FridayParts $430.99 0R-8290 FridayParts $430.99 118-6606 FridayParts $104.45 247-7133 Amazon eBay $107.00 eBay $41.00 FridayParts $27.50 261-6847 FridayParts $112.35 3B-6552 FridayParts $7.51 1W-4879 FridayParts $856.99 124-5572 KuduParts $50.00 189-0202 eBay $60.00 FridayParts $79.99 166-1681 FridayParts $79.99 6I-0273 FridayParts $62.90 6T-0988 FridayParts $45.00 P532474 FridayParts $50.88 6I-0274 FridayParts $50.88 6I-2474 FridayParts $50.88 2G-1034 FridayParts $13.66 8N-1083 FridayParts $534.30 362-4856 FridayParts $450.99 7T-2798 FridayParts $41.23 3T-4615 FridayParts $46.99 117-4013 FridayParts $46.99 7C-9001 FridayParts $18.99 156-0626 FridayParts $159.00 215-9996 FridayParts $110.00 4D-2287 FridayParts $39.92 156-0627 FridayParts $185.00 7T-9307 FridayParts $240.68 6I-2503 Amazon $62.99 eBay $62.99 KuduParts $115.00 6I-2504 eBay $25.99 KuduParts $115.00 8M-3368 FridayParts $27.20 0R-0905 FridayParts $227.40 7E-5996 Amazon eBay $159.99 FridayParts $169.68 8N-1984 Amazon eBay $275.00 FridayParts $114.19 148-8339 FridayParts $42.89 6V-8716 FridayParts $42.89 171-9816 FridayParts $1004.56 142-1931 FridayParts $1195.00 9Y-2988 FridayParts $40.68 142-5867 eBay $41.66 FridayParts $39.38 6Y-2065 FridayParts $160.14 6K-5528 FridayParts $60.00 212-5883 FridayParts $156.66 124-1855 FridayParts $22.23 1B-7709 FridayParts $19.99 197-9322 FridayParts $92.88 478-7932 FridayParts $1190.94 11R-0332 FridayParts $1190.94 20R-8181 FridayParts $1190.94 351-8758 SinoCMP $1069.00

Parts listed by aftermarket suppliers as fitting this engine — leads compiled from supplier catalogs; verify the exact part for your serial number.

Filters for this engine

Air filter: Caterpillar 612506 Donaldson P532506 Wix 46589 Ac Delco A1586C
Oil filter: Caterpillar 3890434 Caterpillar 2P4005 Donaldson P551808 Donaldson P554005 Wix 57792 Wix 51792 Ac Delco PF879L

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 587R — Pipe Layer
Caterpillar 980G II — Loader Wheeled
Caterpillar R2900 — Loader Wheeled
Caterpillar RM250C — Road Stabilizer
Caterpillar RM350 — Road Stabilizer
Caterpillar RR250B — Road Stabilizer
Caterpillar SS250B — Road Stabilizer
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

What is the oil capacity of the Caterpillar 3406C?

The Caterpillar 3406C engine has an oil capacity of 34.0 liters.

What is the displacement of the Caterpillar 3406C?

The Caterpillar 3406C has a displacement of 14.0 liters with 6 cylinders.

Which generators use the Caterpillar 3406C engine?

The Caterpillar 3406C powers 2 generator set(s), including Caterpillar 3406, Caterpillar 3406C Industrial Engine.

What oil filter does the Caterpillar 3406C use?

The Caterpillar 3406C uses oil filter part numbers Caterpillar 3890434, Caterpillar 2P4005, Donaldson P551808.

What air filter does the Caterpillar 3406C use?

The Caterpillar 3406C uses air filter part numbers Caterpillar 612506, Donaldson P532506, Wix 46589.

How often should you change the oil in the Caterpillar 3406C?

The Caterpillar 3406C oil change interval is every 250 hours.

What is a common problem with the Caterpillar 3406C engine?

A commonly reported issue on generators using the Caterpillar 3406C is: Fault shutdown.