John Deere 4276T Specifications
| Engine Model: John Deere 4276T |
| Engine Type: 4-cycle inline 4-cylinder turbocharged liquid-cooled diesel |
| Total Displacement: 276 cu.in (4.5 L) |
| Rated Engine Power: 90-110 Hp (67-82 kW) at 2500 rpm |
| Fuel System Type: Direct fuel injection |
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The John Deere 4276T is a 4.5-liter,
four-cylinder, turbocharged diesel engine engineered for heavy-duty
industrial and construction applications. This power plant is a direct
injection, four-stroke design that leverages forced induction to deliver
increased power and torque density from its displacement. The engine is
constructed for durability and sustained performance in high-load
environments, featuring a robust cylinder block, wet sleeve liners, and
a gear-driven camshaft.
The 4276T is distinguished by its mechanical fuel system, which provides
reliable operation and straightforward serviceability in field
conditions. This model serves as a prime power source for a range of
John Deere construction equipment, including loaders, dozers, and
excavators, where dependable torque and responsive power are required.
Engine Type: 4-cylinder, inline, 4-stroke cycle, vertical,
liquid-cooled, turbocharged diesel.
Combustion System: Direct injection.
Aspiration: Turbocharged.
Rotation: Counterclockwise when viewed from the flywheel end.
Firing Order: 1-3-4-2.
Bore: 106.0 mm (4.19 inches).
Stroke: 127.0 mm (5.00 inches).
Displacement: 4.5 liters (276 cubic inches).
Compression Ratio: 16.0:1.
Governor Type: Mechanical, all-speed.
Rated Power Output: ratings range from 67 to 82 kW (90 to 110 Hp) at
2500 crankshaft rpm.
Maximum Torque Output: ratings range from 360 to 400 Nm (265 to 295
lb-ft).
High Idle Speed: Governed setting, commonly 2625 rpm.
Low Idle Speed: 800 to 850 rpm.
Fuel Shutoff: Electric solenoid, 12 Volt or 24 Volt system.
Dry Weight (Approximate, base engine): 204 kg (450 lbs).
The cylinder block is a single-piece, high-strength gray iron casting
with a deep-skirt design. This construction provides a rigid foundation
for the rotating and reciprocating assembly, minimizing flex and
vibration. The block incorporates replaceable, press-fit wet-type
cylinder sleeves. These sleeves are manufactured from centrifugally cast
alloy iron, offering high wear resistance and efficient heat transfer to
the coolant.
The crankshaft is supported by five main bearings with steel-backed,
tri-metal aluminum alloy bearing inserts. Main bearing caps are ductile
iron and are secured with two vertical bolts per cap. The block features
precision-machined bores for the camshaft and auxiliary drive gears,
along with internal oil galleries and coolant jackets surrounding each
cylinder sleeve.
The cylinder head is a single-piece, cast iron component with crossflow
porting. It is secured to the block with high-tensile steel cap screws.
The head accommodates two valves per cylinder: one intake and one
exhaust. Valve seats are induction-hardened. Intake valves are
manufactured from chrome-plated steel. Exhaust valves are produced from
heat-resistant steel with Stellite-faced heads to withstand the elevated
temperatures from turbocharged operation.
Valve guides are replaceable. Valve actuation employs individual,
shaft-mounted rocker arms. Valve lash is adjusted via screw-type
adjusters on the rocker arms. The camshaft, located in the cylinder
block, operates the valves through solid lifters and pushrods. A
multilayer steel head gasket seals the combustion chamber and fluid
passages.
The fuel system is a direct injection, pump-line-nozzle configuration. A
camshaft-driven, rotary-type transfer pump supplies fuel from the tank.
Fuel passes through a primary filter with a water separator and a
secondary spin-on filter. The injection pump is a distributor-type unit
(John Deere DB2 or DB4 rotary pump) with an integral mechanical
governor. The governor controls fuel delivery to maintain engine speed
under varying load conditions.
High-pressure fuel lines connect the distributor pump to each injector.
The injectors are multi-hole, pencil-type units that atomize fuel
directly into the combustion chamber. An electric solenoid, activated by
the ignition switch, provides positive fuel shutoff. Some applications
may include an aneroid device on the injection pump to moderate fuel
delivery based on intake manifold pressure.
The lubrication system is a force-feed, full-flow design. A gear-type
oil pump, driven from the front gear train, draws oil from the oil pan
through a pickup tube and screen. Pressurized oil is routed through a
full-flow, spin-on oil filter. Filtered oil is distributed via main
galleries to the crankshaft main bearings, connecting rod bearings,
camshaft bearings, and the valve rocker shaft.
A piston cooling jet sprays oil onto the underside of each piston crown.
The turbocharger center bearing cartridge receives oil from a dedicated
feed line, with drain oil returning to the oil pan. A pressure relief
valve, integral to the oil pump, maintains system pressure within design
limits. Total oil system capacity is 12.0 liters (12.7 U.S. quarts)
including filter. Engine oil meeting performance classification CF-4 or
higher is specified.
The cooling system is a pressurized, liquid-cooled design. A centrifugal
water pump, gear-driven from the front of the engine, circulates
coolant. Coolant flow is directed first through the cylinder block,
around the wet sleeves, then upward into the cylinder head, and finally
to the radiator. A wax-pellet-type thermostat regulates operating
temperature by controlling coolant flow to the radiator.
System pressure is maintained by a radiator pressure cap, commonly rated
for 83 kPa (12 psi). The system includes a coolant bypass circuit for
temperature regulation during warm-up. Airflow across the radiator is
provided by a belt-driven fan or a hydraulic fan drive, depending on the
application. Total coolant capacity is 19.0 liters (20.1 U.S. quarts). A
50/50 mixture of ethylene-glycol antifreeze and water is required.
Turbocharger System: The engine is equipped with a wastegated
turbocharger. The turbocharger compresses intake air, increasing charge
density for greater power output. The wastegate regulates maximum boost
pressure to protect the engine.
Electrical System: The engine employs a 12 Volt or 24 Volt electric
starting motor. A 12 Volt or 28 Volt alternator provides charging
current. Intake manifold glow plugs, controlled by a timer relay, assist
in cold-weather starting. Flywheel and Housing: A SAE standard flywheel
housing is used. The flywheel is a machined cast iron component.
Air Intake System: A dry-type, replaceable paper element air cleaner is
standard. Intake air passes from the cleaner through the turbocharger
compressor and then through an intercooler (if equipped) or directly to
the intake manifold. Exhaust System: Exhaust gases exit the exhaust
manifold and drive the turbocharger turbine before exiting the exhaust
system.
Overall Length (Front of damper to flywheel housing face): 910 mm (35.8
inches)
Overall Width (Maximum at turbocharger/intake manifold): 740 mm (29.1
inches).
Overall Height (Top of valve cover to oil pan rail): 850 mm (33.5
inches).
Dry Weight (Base engine, less coolant and oil): 204 kg (450 lbs).
Engine Oil Change Interval: 250 service hours or 6 months. Severe
service conditions (extreme dust, high idle time) mandate reduced
intervals. Oil Filter Change: Replace with every oil change. Fuel Filter
Service: Drain water from primary separator daily; replace primary and
secondary filter elements every 500 service hours. Air Filter Element
Service: Service using dry methods every 100 service hours; replace
element based on restriction gauge reading. Coolant Change Interval:
3000 service hours or 3 years.
Valve Lash Adjustment (Cold Engine Setting): Intake valve: 0.15 mm
(0.006 inches); Exhaust valve: 0.20 mm (0.008 inches). Inspect and
adjust every 1000 service hours. Turbocharger Inspection: Check for
axial and radial shaft play every 2000 service hours. Injection Nozzle
Service: Test spray pattern and opening pressure every 2000 service
hours. Fan Drive Belt Tension: Adjust to provide 13 mm (0.5 inches) of
deflection at the belt's longest span under moderate thumb pressure.
Cylinder Head Bolts: Torque in specified sequence to 95 Nm (70 lb-ft),
then to 120 Nm (89 lb-ft), final angle tighten + 90 deg.
Main Bearing Cap Bolts: 190 Nm (140 lb-ft).
Connecting Rod Cap Nuts: 115 Nm (85 lb-ft), then final tighten an
additional 60-degree turn.
Flywheel to Crankshaft Bolts: 160 Nm (118 lb-ft).
Rocker Arm Shaft Bracket Bolts: 55 Nm (41 lb-ft).
Injector Clamp Bolt: 35 Nm (26 lb-ft).
Turbocharger Mounting Nuts: 35 Nm (26 lb-ft).
Oil Pan Bolts: 24 Nm (18 lb-ft).
The John Deere 4276T engine is a designated power plant for a series of
John Deere construction and forestry machinery. Key applications include
John Deere tractor loaders such as the 410C, 410D, 510B, and 444G
models. It is also the installed engine in John Deere crawler dozers,
including the 450E, 450F, 450G, 550, 550A, 550B, and 550G series.
Furthermore, this engine powers various John Deere excavators, skidders,
and other specialized industrial equipment requiring a robust,
turbocharged diesel in the 90 to 110 Hp class. Its mechanical fuel
system and proven architecture ensure compatibility with the operational
and maintenance demands of the construction industry.
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