FOURTH GEAR POWERFLOW
Speed and torque are not converted by the direct
gear ratio of the 4th gear. Power is transferred from
the drive shaft (25) to the output shaft (26) via three
locked planetary gearsets (Fig. 8) and (Fig. 9).
Front Planetary Gear Set
The planetary carrier (13) and sun gear (21) are
connected via the engaged multiple-disc clutch K1
(7). The planetary gearset is therefore locked and
turns as a closed unit at the input speed due to the
mechanical connection of the annulus gear (8) and
the drive shaft (25).
Rear Planetary Gear Set
The multiple-disc clutch K2 (9) is engaged and
transfers the input speed of the drive shaft (25) to
the planetary carrier (15) via the annulus gear (10).
The annulus gear (11) turns in the same way as the
planetary carrier (15) due to the mechanical connec-
tion with the locked front planetary gearset. The
planetary gearset is therefore locked and turns as a
closed unit.
Center Planetary Gear Set
The annulus gear (10) turns at the input speed as
a result of the engaged multiple-disc clutch K2 (9).
The multiple-disc clutch K3 (12) connects the sun
gears (22) and (23) of the rear and center planetary
gearset. The planetary gearset is locked by the same
speeds of the annulus gear (10) and the sun gear (22)
and it turns as a closed unit.
Fig. 8 Fourth Gear Powerflow
1 - TORQUE CONVERTER LOCK-UP CLUTCH
14 - CENTER PLANETARY CARRIER
2 - TORQUE CONVERTER TURBINE
15 - REAR PLANETARY CARRIER
3 - TORQUE CONVERTER IMPELLER
16 - TORQUE CONVERTER STATOR
4 - HOLDING CLUTCH B1
17 - FRONT PLANETARY PINION GEARS
5 - HOLDING CLUTCH B3
18 - CENTER PLANETARY PINION GEARS
6 - HOLDING CLUTCH B2
19 - REAR PLANETARY PINION GEARS
7 - DRIVING CLUTCH K1
20 - FREEWHEELING CLUTCH F1
8 - FRONT PLANETARY ANNULUS GEAR
21 - FRONT PLANETARY SUN GEAR
9 - DRIVING CLUTCH K2
22 - CENTER PLANETARY SUN GEAR
10 - CENTER PLANETARY ANNULUS GEAR
23 - REAR PLANETARY SUN GEAR
11 - REAR PLANETARY ANNULUS GEAR
24 - FREEWHEELING CLUTCH F2
12 - DRIVING CLUTCH K3
25 - DRIVE SHAFT
13 - FRONT PLANETARY CARRIER
26 - OUTPUT SHAFT
A - ENGINE SPEED
B - TRANSMISSION INPUT SPEED
WG
TRANSMISSION AND TRANSFER CASE
21a - 11
AUTOMATIC TRANSMISSION - W5J400 (Continued)