SsangYong Korando III (2010 year). Service manual — part 94

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2) Operation of DMF

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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Compression stroke

Combustion stroke

Small changes from engine (k):
Damper increases the torque changes to clutch

Large changes from engine (j):
Damper decreases the torque changes to
transaxle by absorbing the impact

Torque change curve of engine and drive shaft

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3) Features of DMF

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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4) Advantages of DMF

Improved torque response by using 2-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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Components

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.

Overview

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Layout and Components

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Top

Bottom

Oil ring

Piston ring

No.1 ring

Piston pin

No.2 ring

Snap ring

Piston

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Functions

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Piston transfers the combustion energy from engine to connecting rod.

C. Snap ring

Locks the piston pin.

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A. Piston ring

#1 ring (Top ring) : Prevents the high pressurized combustion gas from leaking into crank chamber,

and prevents the engine oil getting into combustion chamber.

#2 ring: Scrapes the engine oil on the cylinder bore, and prevents the leaked combustion gas from #1

ring from leaking into the crank chamber.

Oil ring: Scrapes the engine oil on the cylinder bore.

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B. Piston pin

Connects the piston the connecting rod, and transfers the linear movement of piston to connecting rod

to convert it to rotating energy.

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Piston ring

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Piston ring end gap (mm)

#1 end gap: 0.170 ~ 0.320
#2 end gap: 0.300 ~ 0.450

Piston ring side clearance (mm)

#1 groove: 0.040 ~ 0.080
#2 groove: 0.040 ~ 0.080