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Screw plug
Oil sealTiming gear case cover
Timing gear case cover (TGCC)
(5) Timing gear case cover
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Features
Major function: Protecting the chain drive system, minor function: Shielding the chain noise.
Install crankshaft front seal and screw plug on the timing gear case cover. ▶
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Do not touch the inner lip of crankshaft front seal.
Be careful not to damage the screw thread when removing the lock pin to release the chain
tensioner.
Be careful not to damage the O-ring when installing the screw plug. -
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A671 997 01 46
Crankshaft front seal
Location of chain tensioner
screw plug
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Oil pan sassembly
8. OIL PAN
The oil pan in D20DTR engine improves the NVH. Especially, the oil draining is much easier than
before.
Components ▶
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9. DUAL MASS FLYWHEEL (DMF) & DRIVE PLATE
1) Overview
Flywheel is installed on crankshaft. When
starting the engine, this functions as follows:
Reducing the irregular speed of crankshaft
due to unbalanced combustion -> Improving
the power train NVH, Improving the driving
performance
Reducing the clutch noise by using ball
bearing
Improving the durability of DMF by using
strong arch spring -
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-
2) Layout
Spring guide
Drive plate
Primary cover
Primary flywheel
Internal/external ringSecondary flywheel
Ring gear
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Torque change curve of engine and drive shaft
Compression stroke Combustion stroke
Small changes from engine (k):
Damper increases the torque changes to clutchLarge changes from engine (j):
Damper decreases the torque changes to
transaxle by absorbing the impact
3) Operation
Compensating the irregular operation of engine: The secondary flywheel operates almost evenly
so does not cause gear noises
The mass of the primary flywheel is less than conventional flywheel so the engine irregularity
increases more (less pulsation absorbing effect).
Transaxle protection function: Reduces the torsional vibration to powertrain (transaxle) by reducing
the irregularity of engine. -
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4) Features
Reduced vibration noise from the powertrain by blocking the torsional vibrations
Enhanced vehicle silence and riding comforts: reduced engine torque fluctuation
Reduced shifting shocks
Smooth acceleration and deceleration -
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-
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5) Advantages
Improved torque response by using 3-stage type spring: Strengthens the torque response in all
ranges (low, medium, and high speed) by applying respective spring constant at each range.
Stable revolution of the primary and secondary wheel by using planetary gear: Works as auxiliary
damper against spring changes
Less heat generation due to no direct friction against spring surface: Plastic material is covered on
the spring outer surface
Increased durability by using plastic bushing (extends the lifetime of grease) -
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6) Drive Plate
Drive plate receives the power from the start motor when starting the engine. With this, the drive plate
initially drives the power train system. And, it is connected to the torque converter to transfer the engine
torque to the power train system.
Trigger ring
Drive plate
Components ▶
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10. PISTON/CRANKSHAFT/CYLINDER BLOCK
The crankshaft and the cylinder block convert the compression pressure to the rotating energy.
Components ▶
Cylinder block
Piston
Connecting rod
Crankshaft
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1) Piston
(1) Overview
Piston assembly contains piston, #1 ring, #2
ring, oil ring, piston pin and snap ring. The
expansion energy from engine is transferred to
the crankshaft through connecting rod to
convert the linear movement to rotating energy.
(2) Layout
#1 ring
Oil ring
Snap ring
#2 ring
Material:
B2+
Skirt coating:
MoS2
Piston cooling gallery
for connecting rod
Wide bawl type (CR 16.5)
Cooling jet