John Deere 4045HF120 Specifications
| Engine Model: John Deere PowerTech 4045HF120 |
| Engine Type: 4-stroke in-line 4-cylinder turbocharged liquid-cooled diesel |
| Total Displacement: 275 cu.in (4.5 L) |
| Rated Engine Power: 115 Hp (86 kW) at 2400 rpm |
| Fuel System Type: Direct Injection |
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The John Deere 4045HF120 is a 4.5-liter,
4-cylinder diesel engine from the PowerTech 4045 family, representing a
High-pressure Turbocharged and Aftercooled configuration, as indicated
by the HF designation. This engine is engineered for intermittent
industrial and off-highway applications requiring a balance of high
torque rise and fuel efficiency.
It operates on a mechanical fuel system, providing field serviceability
without specialized electronic diagnostic equipment. The 4045HF120 is an
interim Tier 2 / Stage II compliant unit, widely deployed in
construction machinery, agricultural implements, and stationary power
units demanding robust, low-speed torque characteristics. Its wet-sleeve
cylinder design and five-main-bearing crankshaft deliver structural
integrity for sustained high-load operation.
The 4045HF120 follows John Deere’s proven in-line architecture,
optimized for torque density and thermal management under continuous
intermittent duty cycles.
Engine Type: 4-cycle, in-line, 4-cylinder diesel
Displacement: 4.5 L (275 cu.in)
Bore x Stroke: 106 mm x 127 mm (4.19 in x 5.00 in)
Compression Ratio: 17.0:1
Firing Order: 1-3-4-2
Rotation (facing flywheel): Counterclockwise
Rated Power (Intermittent): 86 kW (115 hp) at 2400 rpm
Peak Torque: 476 Nm (351 lb-ft) at 1400 rpm
Rated Speed: 2400 rpm
Low Idle Speed: 800-950 rpm
Aspiration: Turbocharged with air-to-air aftercooling
The cylinder block is constructed from high-grade cast iron with a
deep-skirt design to maximize rigidity. It employs replaceable
wet-sleeve cylinder liners, which are free-standing and sealed at the
lower end by O-rings and at the upper end by a compressed metal gasket.
This liner design facilitates rapid heat transfer to the coolant and
allows in-chassis overhaul without reboring the parent bore.
The block houses five main bearings with the crankshaft supported by
forged steel main bearing caps. Honing patterns on the liner inner
surfaces are plateau-finished to promote oil retention and rapid ring
seating. Water jackets surround each liner fully, ensuring uniform
cylinder temperature across the entire length of the piston stroke.
The cylinder head is a single-piece cast iron unit, chosen for thermal
expansion compatibility with the block. It utilizes an overhead valve
(OHV) layout with pushrods and rocker arms actuated by a camshaft
mounted within the block. Each cylinder receives two valves: one intake
and one exhaust.
Intake valves are larger in diameter to maximize air swirl, a critical
factor for mechanical injection combustion efficiency. Valve seats are
induction-hardened and replaceable. The cylinder head is secured by
multiple high-strength bolts arranged in a non-symmetric pattern to
distribute clamping force evenly across the fire deck. Valve guides are
pressed-in and machined post-assembly for precise concentricity with
valve seats.
The fuel system is a mechanical direct injection arrangement centered on
a Stanadyne DB4 series rotary distributor pump. This pump is
engine-lubricated and gear-driven from the front timing case. It
generates injection pressures sufficient for indirect or direct chamber
designs without electronic control. The pump incorporates a mechanical
governor that regulates fuel delivery based on engine speed and load,
providing droop characteristics suitable for generator sets and
hydraulic power units.
High-pressure fuel lines of equal length route from the pump to
individual spring-loaded injectors. Each injector opens at a
predetermined pressure, producing a multi-hole spray pattern. Excess
fuel bypasses the pump and returns to the tank, aiding in cooling of the
injection components. A manual primer pump and a replaceable fuel filter
with a water separator are mounted on the engine.
The lubrication system operates as a pressurized wet-sump configuration.
A crankshaft-driven gear-type oil pump is housed within the front cover.
Oil is drawn through a strainer from the sump, passed through a
full-flow spin-on filter, and then routed to the main oil gallery. The
gallery distributes oil to the crankshaft main bearings, connecting rod
bearings, camshaft bearings, and rocker shaft assembly.
Piston cooling jets are not featured on this HF variant; thermal
management relies on the wet liners. Oil pressure is monitored by a
sender unit providing analog data to panel gauges or warning switches.
Bypass valves in the filter head permit oil flow if the filter becomes
restricted.
Oil Capacity (with filter): 12.0-13.2 L (12.7-13.9 qt).
Oil Pressure (rated speed): 35-50 psi (241-345 kPa).
The cooling system uses a centrifugal water pump driven by the
serpentine belt. Coolant circulates through the block water jackets
around each wet liner, then upward through cylinder head passages. A
bypass circuit allows coolant to recirculate during warm-up until the
thermostat opens. The thermostat, rated at 82°C (180°F), is mounted in a
housing on the front of the cylinder head.
From the thermostat housing, coolant exits to the radiator or
aftercooler circuit. The air-to-air aftercooler system operates
separately; compressed intake air passes through a stand-alone radiator
core, not through engine coolant. This design maintains lower intake air
temperatures independent of engine coolant temperature. Coolant Capacity
(engine only): 8.5 L (9.0 qt).
| Intake and Exhaust Systems |
Air Intake System: Dry-type replaceable element air cleaner with a
restriction indicator. Turbocharger is a fixed-geometry unit; the HF
suffix indicates a higher boost pressure capability compared to
naturally aspirated or turbo-only 4045 variants.
Exhaust System: Optional exhaust manifold configurations include dry or
water-cooled for marine or enclosed generator installations. No
aftertreatment devices are required for this emission level.
12-volt (standard) or 24-volt (optional). Starter motor is a
reduction-gear type. Alternator output varies by application, from 40
amperes to 120 amperes.
Length: 861 mm (33.9 in)
Width: 612 mm (24.1 in)
Height: 951 mm (37.4 in)
Dry Weight (without flywheel, alternator, starter): 451 kg (994 lb)
Weight (fully dressed with standard accessories): 495 kg (1091 lb)
Oil Change Interval: 250 hours under normal industrial duty.
Oil Grade (recommended): SAE 15W-40 meeting API CI-4 or higher.
Oil Filter: Spin-on full-flow type, change at every oil change.
Fuel Filter Change Interval: 500 hours or annually.
Intake Valve Lash (cold): 0.36 mm (0.014 in).
Exhaust Valve Lash (cold): 0.46 mm (0.018 in).
Valve Lash Inspection Interval: 1000 hours.
Coolant Type: Heavy-duty diesel antifreeze with nitrite-based.
Coolant Change Interval: 2000 hours or 2 years.
Air Cleaner Element: Replace when restriction indicator shows red.
Injection Timing (static): 12° BTDC (before top dead center) on No. 1
cylinder.
Cylinder Liner Protrusion: 0.03-0.08 mm (0.0012-0.0031 in) above block
deck.
Cylinder Head Bolts (final step sequence): 150 Nm (110 lb-ft).
Connecting Rod Bolts: 115 Nm (85 lb-ft).
Main Bearing Cap Bolts: 135 Nm (100 lb-ft).
Flywheel Bolts (to crankshaft flange): 115 Nm (85 lb-ft).
Flywheel Housing to Block Bolts: 60 Nm (44 lb-ft).
Rocker Arm Shaft Bracket Bolts: 25 Nm (18 lb-ft).
Injector Clamp Nuts: 28 Nm (21 lb-ft).
Fuel Injection Pump Mounting Nuts: 24 Nm (18 lb-ft).
Valve Cover Bolts: 12 Nm (9 lb-ft).
Oil Pan Bolts: 22 Nm (16 lb-ft).
The John Deere 4045HF120 serves in original equipment manufacturer (OEM)
roles across construction, agriculture, and industrial sectors.
Construction Equipment: John Deere 120-series excavators, 644G and 744H
loaders (hydraulic power module), 770G graders, and 318G skid steers as
an auxiliary power unit. Also used in JLG telehandlers, Genie boom
lifts, and Ingersoll Rand compactors.
Agricultural Machinery: Mid-sized tractors including John Deere 5100E,
5400 series utility tractors. Found in self-propelled sprayers (John
Deere 4730) and certain forage harvester configurations.
Industrial Power Units: Stationary applications such as wood chippers
(Bandit, Morbark), hydraulic power packs for municipal equipment, air
compressors (Sullair, Atlas Copco), and irrigation pump drives.
Marine (limited): Small workboats and auxiliary generators where
mechanical simplicity and saltwater corrosion resistance are
prioritized.
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