Hydraulic System Operation; Planetary Gear Train; Roller Clutches; Governor - Jeep 1979 CJ-5 Technical & Service Manual

AUTOMATIC TRANSMISSON 2C-3
T U R B I N E S T A T O R C O N V E R T E R PUMP
T U R B I N E
S H A F T
J 4 2 4 2 5
Fig. 2G-2
Torqisa Converter
6 0 5 2 3
Fig. 2C-3 Detent Switch
direct clutch apply pressure, reroutes apply pressure
into the intermediate clutch and downshifts the trans-
mission to second gear. Downshifts occur at speeds be-
low approximately 65 mph (105 km/h).
The manual linkage provides the mechanical con-
nection between valve body manual valve and column-
mounted gearshift lever. The linkage allows the driver
to select the desired transmission gear range.
Planetary Gear Train
The planetary gear train consists of four members: a
sun gear, two planet carriers, each having four pinion
gears, and an internal gear (fig. 2C-1). The sun gear
meshes with the planet pinion gears, which rotate freely
on pins attached to a common support called the planet
carrier. An internal gear encases the assembly and
meshes with the planet pinion gears.
Roller' ditches
A roller clutch permits rotation of a unit in one direc-
tion only. Roller clutches are used to lock one member of
each planetary gear set for gear reduction. The inter-
mediate roller clutch is effective in second gear D or 2-
range only. The low roller clutch is effective in first gear
D or 1-range only. In direct drive (third gear), the roller
clutches allow free rotation of all members.
HYDRAULIC SYSTEM OPERATION .
Pressure Control
Hydraulic system pressure is developed and supplied
by the gear-type oil pump which is driven by the torque
converter pump. Main line pressure is determined by a
pressure regulator valve located in the pump housing.
This valve regulates line pressure automatically and in
response to vacuum signals from the modulator valve.
Vacuui Modulator
The engine-to-transmission vacuum signal is provided
by the vacuum modulator which consists of an evac-
uated metal bellows, a diaphragm, and two springs. The
bellows and one spring apply a force which acts on the
modulator valve to increase modulator pressure. Engine
vacuum and the second spring act in the opposite direc-
tion to decrease modulator pressure. Low engine vac-
uum results in high modulator pressure, while high
engine vacuum results in low modulator pressure.
Governor
The vehicle speed signal to the modulator valve is
supplied by the centrifugal governor which is driven by
the transmission output shaft. The governor consists of
two sets of centrifugal weights, two springs, and a regu-
lator valve. Centrifugal force acting on the governor