Fiat Bravo Service Manual page 489

Auto transmission and differential
Components and operation
21-27.
T h i r d g e a r (selector lever on position D-3)
The gearbox input shaft E rotates in a clockwise direction.
The crownwheels K1 and K 2 are coupled to the input shaft E by the engagement of the clutch C I ,
clutch carrier drum D and the clutches C 3 and CO.
The clutch C 3 locks the free wheel FO.
The epicyclic gear sets P I (S1 - ST1 - K1) and P2 ( S 2 - S T 2 - S T 3 - K2) lock onto each other w h e n
their transmission ratios are different.
F o u r t h gear (selector lever on position D)
The gearbox input shaft E rotates in a clockwise direction.
The crownwheel K 2 is coupled to the input shaft E by the engagement of the multiple disc clutch C I ,
the clutch carrier drum D and the clutch CO.
The free wheel FO allows the crownwheel K1 to rotate in a clockwise direction.
The sun gear S 2 is locked on the gearbox casing by the engagement of the band brake B1.
12
Bravo-Brava i f l ^
The planet gears S T 1 , S T 2 and
S T 3 , locked, drive the gear train
carrier T I in a clockwise direction
at the same speed as the input
shaft E (ratio 1:1).
The gear 11 transmits motion to the
wheels via the gear 12 and the dif-
ferential relay shaft U.
The planet gears S T 2 , driven by
the crownwheel K 2 via the planet
gears S T 3 , shift onto the locked
zzzy
sun gear S 2 , rotating the gear train
carrier T1 in a clockwise direction.
The clockwise shift of the gear
train carrier T I makes the planet
gears S T 2 rotate in a clockwise d i -
rection on the locked sun gear S 2
and the planet gears S T 3 in an a n -
ti-clockwise direction.
The anti-clockwise rotation of the
planet gears S T 3 on the c r o w n -
wheel K 2 achieves a further i n -
crease in clockwise rotation of the
gear train carrier T I .
The result is that the speed of the
gear train carrier T I and the gear II
is higher than that of the driving
crownwheel K2, obtaining 4th gear.
Publication no. 506.670/06