SMART 453 Series Introduction Into Service Manual page 54

Shift mechanism
On the twinamic 6-speed dual clutch transmission, the en-
gine torque is transferred from the crankshaft of the combus-
tion engine to a two-mass flywheel. From there, the power
flows to the internal shaft or external shaft of the dual clutch
transmission depending on the clutch engaged. A single-cone
carbon synchronizer is used to synchronize the first, third,
fourth and reverse gear. A double-cone sintered synchronizer
is used for the second gear. Synchronization of the fifth to
the sixth gear is carried out with a single-cone sintered syn-
chronizer. The transmission operates without an additional oil
cooling system.
1
Shift mechanism of dual clutch transmission
1 1st gear
2 2nd gear
Introduction of the New smart fortwo coupé and smart forfour | Model Series 453
– This printout will not be recorded by the update service. Status: 06/2014 –
twinamic 6-speed dual clutch transmission
Process
During driving operation, a gear is always engaged in each of
the two sub-transmissions. The gear which is expected to be
engaged next is pre-engaged in the second sub-transmission
by the transmission control system. The clutch for the gear
currently in use is engaged, while that of the gear which is
expected to be used is disengaged. To change gears, clutch 1
(currently engaged) is opened, while clutch 2 is engaged.
Summary
The dual clutch transmission operates without any interrup-
tion of tractive power. If necessary, the electronic control
system skips individual gear ranges instead of downshifting
the gears one after the other. It thus provides the conveni-
ence of an automatic transmission combined with the effici-
ency of a manual transmission.
2
Sub-transmission 1: 1st, 3rd, 5th gear
Sub-transmission 2: 2nd, 4th, 6th, R gear
P27.00-2444-00
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