torque DATSUN 210 1979 Manual PDF

Page 255 of 548


Automatic
Transmission

HYDRAULIC
CONTROL
UNIT
AND

VALVES

The

hydraulic
or
a
tomatic
control

system
is

comprised
of
four
4
basic

groups
the

pressure
supply
system

the

pressure
regulating
system
the

flow
control
valves
and
the
friction

elements

PRESSURE
SUPPLY
SYSTEM

The

pressure
supply
system
consists

of

a

gear

type
oil

pwnp
driven

by
the

engine
through
the

torque
converter

The

pump
provides

pressure
for
aU

hydraulic
and
lubrication
needs

PRESSURE
REGULATOR

VALVES

The

pressure
regulating
valves
con

trol
the

output
pressure
of
the
oil

pump

Pre
ure

rellulator
valve

The

pressure
regulator
valve
con

trois
mainline

pressure
based
on

throttle

opening
for
the

operation
of

the
band
clutches
and

brake

Governor

valve

The

governor
valve
transmits

re

gulated
pressure
based
on
car

peed

to
the

shift
valves
to
control

upshifts

and
downshifts

Vacuum
throttle
valve

The
vacuum

throttle
valve
transmits

regulated
pressure
based
on

engine

load
vacuum
This

pressure
controls

the

pressure
regulator
valve

Also
this

pressure
is

applied
to
one
end
of
the

shift
valves
in

opposition
to

governor

pressure
which
acts

on
the
other

end

of
the
shift
valves

controlling

upshift

and
downshift

speeds
FLOW
CONTROL
VALVES

Manual
valve

The
manual
valve
is
moved

manual

Iy
by
the
car

operator
to
select
the

different
drive

ranges

1
2
ShHt
valve

The
1
2

shift
valve

automaticaIly

shifts
the
transmission
from
first

to

second
or
from
second
to
first

depend

ing

upon
governor
and
throttle

pres

sure

along
with

accelerator

position

solenoid
downshift
valve
See

Hy

draulic
Control
Circuits
Drive

2

2
3
ShHt
valve

The
2
3
shift
valve

automaticaIly

shifts
the
transmission
from
second
to

top
gear
or
from

top
to
second
de

pending

upon
governor
and
throttle

pressure
or
accelerator

position
sole

noid
downshift
valve

See
Hydraulic

Control
Circuits
Drive
3

Range

2
3

Tlmlnll
valve

For
2
3
shifts
a
restrictive
orifice

slows
the

application
fluid
to
the
front

clutch
while
the

slower

reacting
band

is
allowed
to
release
This

prevents
a

hard
2
3
or
3
2
shift
Under

heavy

load
however
the

engine
will
tend
to

run

away
during
the
2
3

or
3
2
shift

pause
therefore
a
2
3

timing
valve

using
throttle
and

governor

pressure
is

used
to

bypass
the

restrictive
orifice

during
such

heavy
load
conditions

Solenoid
down
hHt
valve

The
solenoid
downshift
valve
is

activated

electrically
when
the
ac

celerator
is
f1oor
d

causing
a
forced

downshift
from

top
to
second

top
to

first
or

second
to

first

gear
depending

upon
car

speed
governor

pressure

AT
3
Pre
ure
modified
valve

The

pressure
modifier

valve
assists

the
mainline

pressure

regulator
valve
in

lowering
mainline

pressure
during

high

speed

light
load
conditions
such
as

steady

speed
cruise

Governor

pres

sure

working

against
a

spring

opens

the

valve
which
aUows

modified
throt

tle

pressure
to
work

against
the

pres

sure

regulator
valve

spring
lowering

mainline

pressure
Lower

operating

pressure
under

light
load

reduces
oil

temperature
and
increases
transmis

sian
life

Throttle
back
up
valve

The
throttle

back

up
valve
assists

the
vacuum
throttle
valve
to

increase

line

pressure
when
the
manual
valve
is

shifted

either
to

2
or
I

range

Second
lock
valve

The

second
lock
valve
is

used
to

bypa
the
1
2

shift
valve

to
maintain

the
band

apply

pressure
in
2

posi

tion
The
valve
is
also
used
as
an
oil

passage
for
the
1
2

shift
valve

band

apply

pressure
in

D2

D3
and

12
Range

CLUTCHES
AND
BAND

SERVOS

The

servo

pistons
of
the
clutches

low

reverse
brake
and

band
are
moved

hydraulically
to

engage
the

clutches

brake
and

apply
the
band
The
clutch

and

brake
istons

are
released

by

spring
tension

and
band

piston
is

released

by
spring
tension

and

hy

draulic

pressure

Page 257 of 548


OIL
CHANNEL

IDENTIFICATION

The
circuit
numbers
shown
in
each

Hydraulic
Control
Circuit
are

classified

as
follows
according
to
the

function

Pressure
source
of
the
line
7

Operating
line

pressure
for

friction
elements

I
2
3
4
5
6

g
9

10
11
12

Auxiliary
line

pressure
13

Torque
converter

pressure
14

Governor

pressure
15

Throttle

system
pressure

16
17
18

19

Oil
pump
discharge
hole
7

f
Torque
converter

pressure
14

Rear
clutch

pressure
1

Front
clutch

pressure
11

W
h0i1
pu
6
suction
hote

e

8

IIlIlJJIII
Automatic
Transmission

L

f

AT106

Fig
AT
5

Oil
Channela
in
Cou
Front
Face

lo
o

o
0

Oil

pump
discharge
hole
7
Governor

pressure
15

1

h

Torque
converter
I

pressure
14
0
0

Servo
release

Rear
clutch

l
press
re

10
r

L

Governor
reed

pressure
1

pressure
1
Servo

tlghtemng

li
nb

o

0

pressure
9

r

Front

clutch
fI
Low
reverse
brake

pressure
12

pressure
11

U
0

111
1

1
P
u
n

e

AT107

ATlOS

Fig
A
T
4

Oil
Channell
in
Oil
Pump
Fig
A
T
6
Oil
Channell
in
Cou
Fac

MECHANICAL
OPERATION

In

the
3N71B
automatic
transmis

sion
each

part
operates
as
shown
in

the

following
table
at
each
gear
select

position
RanKe
Cm

ratio
Clutch
Low
A

Front
Rear

brake
One

w

y

dutch
Parkin

pa
l
Band
servo

Operation
Release

Park
on
on

Reftrst
2
182
on

on
on

Neutral

Dl
Lo
2
458
on

on

Drift
02
Second
1
458
on

03

Top
1
000
on
on
on

2
Second
1
4
8
on
on

12
Second
1458
on
on

Low
2
4
8
on
on

Note
The
low
brake
is

applied
in

11
raiW
to

prevent
free
whee6ng

when
coasting
and
aIlows
engine

braking

AT
5

Page 260 of 548


RANGE
REVERSE

Po

r
flow

With
the
selector

lever
in
R

range
the
front
clutch

is

applied
to

transmit

clockwise

engine
torque

through
the

connecting
shell
to
the

sull
gear
The
clockwise
otation

of
the

sun

gear
causes
the

planet
gears
to

rotate
counterclockwise
With
the
low

and

reverse
brake

holding
the

rear

planet
carrier
the
rear
internal

gear

splined
to
the

output
shaft
turm

counterclockwise
in

a
reduction
ratio

ofapproximately2
18
to
1

Fluid
flow

Manual
Valve
4
Automatic

Tninsmission

Front

gear
set

Rear

gear
ell

Output

Input
throush
front
clutch

Held

by
low
A
reverse
brake

AT329

lW
w

Y

Front
clutch

Rear
clutch

Low
and
reverse
brake

Brake
band
servo

On
way
clutch

5
Throttle
Back

up
Valve
Low
A
reverse
brake
ON

Downshift
Valve

1st

2nd
Shift
Valve
12

6

L
Pressure

Regulator
Valve

2nd
3rd
Shift
Valve

10

AT

8
AT085

ON

OFF

ON

OFF
Preuwe
release

o

ernmnin

F
AT
9
M
hanical

Operation
during
R

Range

13
2nd
3rd
Shift
Valve

L

1st
2nd
Shift
Valve

I
Throttle
Back

up
Valve

y
Low
Reve
Brake

Band
Servo
Release
Side

11
Front

Clut
h

I

Page 261 of 548


Automatic

Transmission

R

ren
e

Rever

Torque
con
r1

ril
j

j

I

f
I

12
C
I

J
111
x
J

0

8

Q

I

II

lr

Vacuum
Throttl

I
old

I
10
J

f
k

JP

L
u
I

lJ

El
J
U

I
II
O
co
l

chell

01

TO

I
drain

fol

il

Xl

tJj

1
J

l
2nd

3rd
Ii

minQ

x

U1
1

21
1

1C
ll

IIF

li@S
OC

II
to
0

r

6

9r3

Q

rm
g

L
1

u
iii

uLrt
23

r

t

@

PRND2
I

I
x
moo

la
OlenOid

Oil
cooler

1Rear
lubr
c

otion

f

L
ohl

r
Front

u

J

I
@2nd
3

Shift

vol

a
IS

I

12

u

l
r

I
3

w

q

r
4

I
l

Secondory

Qo
rnar

01
Primarf

Qo
i1lr
lol

Note
Mork

d
X
Qr

droin

j

Lin

prUltfrt
Go
nor

tced

r
rr
uur

J

G
0
1
1
101

pr
L
J

3
J

Torqu
can
tar

P
Urt

Tn
rotU

pr
ur

AT456

Fig
AT
10
Oil
Pr

lSure
Circuit

Diagram
R

range
Reverse

AT
9

Page 264 of 548


DI
RANGE
LOW

GEAR

Po
r
flow

With
the
shift
selector
in
0
low

gear
engine
torque
is

traJWnitted

through
the

applied
rear

clu
tch
to
the

internal

gear
of
the
front

gear
set
The

c1o
kwise
rotation

o
f
the

front
inter

naI

gear
causes
the
front

planet
gears

to
rotate
clockwise

driving
the

com

pound
sun

gear
counterclockwise
The

front

planetary
carrier
is

splined
to
the

output
shaft
This
cau
the

planet

gears
to
drive
the
sun

gear
instead
of

walking
around
the
sun

gear
This

counterclockwise
rotation
of

the
sun

gear
causes
the
rear

planet
gears
to

rotate
clockwise
With
the
one

way

clutch

holding
the
rear

planet
carrier

the
rear

planetary
gears
turn
the
rear

internal

gear
and

output
shaft
clock

wise
in
a
reduction
ratio

of

approxi

mately
2
46
to
L

Fluid
flow

Manual
Valve

2

3
Automatic
Transmission

Fiont

gear
set
Rear
gear
set

Input
t1uOllsh

rear
clutch

Output
shaft

Held

by
on
way
clutch

Input
from
front

gear
set

Output
to
real

gear
set

AT330

1

J

ld

AT081

Front
clutch

Reu
clutch

Low
and
revcrx
brake

Brake
band
servo

Onto

way
clutch
OFF

ON

OFF

OFF

HOLDING

Fig
AT
12

MochanicaIOp

rationduri

DJ
Ra

Governor
Valve

Pressure
Modifier
Valve
15

2nd
3rd
Shift
Valve

lst
2nd
Shift
Valve

2nd
3rd

Timing
Valve

1st

2nd
Shift
Valve

j
Rear

Clutch

I

Second
Lock
Valve

Second
Lock

Valve

LOrifice

Check

Valve
2nd
3rd

Shift
Valve

AT12

Page 265 of 548


D
ran
Low
r

Oil

pump

l

t

Torque

convlrter

pr
ur

rlgula
Tor

yalvl

t

t

1

L

Line

pr
ur

l

Governor

preslur
Automatic
Transmission

Fr
on1

clutch
Rear

cl
ulch

t

l

Torque
conyert

pressure

Throttle

pr
iur
Brake

ba
n
d

o

h
Band

I
b
rvo

I
Low

0
nd

reven
brQke

t

l

Thralll

pre
ur

t

1V

Governor

pre
sur

AT448

Fig
AT
J3
Oil
Pr
ure
Circuit

Diagrom
D

rang
Low

gear

AT13

Page 266 of 548


D2

RA
NGE
2ND
GEAR

Power
flow

In

02
range
the

brake
band
is

applied
to

hold
the

connecting
shell

and
sun

gear
stationary
Engine

torque
through
the

applied
rear
clutch

is
delivered

to
t
he
int

D
1l

1
gear
of
the

front

gear
set
in
a

clockwise
rotation

Clockwise
rotation
of
the
internal

gear

causes
the

planet
gears
to
walk

around
the

stationary
sun

gear
in

a

clockwise
direction
This
causes
the

output
shaft
which
is

splined
to
the

front

planet
carrier

to
turn
ina
clock

wise

direction
with

a
reduction
ratio

of
about
I
46
to
I

Fluid
flow

As
car

speed
and

governor
pressure

increase
the

governor

pressure
acting

on
the
end
of
the
1

2
shift

valve

Manual
Valve
I
Automatic
Tra

l
mission

Front

Bear
set
Rear

gear
set

Input
throuah
rear
clutch

AT331

1f

j
cW
oo
w

I

ATD79

Front
Clutch

Rearc1utch

Low
and
reverse
brake

Broke
band

One
way
clutch
OFF

ON

OFF

ON

OFF

AT447

F
S
AT
14
MechanicalOperation
during

DJ
Range

overcomes
the
force
of
the
1
2

shift

valve

spring
and
line

pressure
This

allows
the

1
2
shift

valve
to
move
to
the

upshift
position
which
directs
line

pressure

through
the

2nd
lock
valve

and

on
to
the
brake
band

Governor
Valve

15
Pressure
Modifier
Valve

2nd
3rd

Timing
Valve

2nd
3rd
Shift
Valve

1st
2nd
Shift
Valve

econd
Lock
Valve
9

Band
Servo

I
Apply
Side
1st
2nd
Shift
Valve
8

l
Rear

CIutclt

I

Second

Lock
Valve
2

3
Second
Lock
Valve

L

Orifice
Check
Valve
2nd
3rd
Shift
Valve

AT
14

Page 267 of 548


0
ren
e
2nd

gear

1
Oil

pump

l
t

ra

d

l

t
Tor

q
UI

convlrt
r

Prlssure

rlQulotor

valvl
Automatic
Transmission

Front

clutch

tt1t

P
RN021
Rear

clutch
Brake

band
LOllii
ond

rlverse
brake

Govern
or

preslure
t

Line

pressure

Governor

pre
ur

j

iiiiB
Torque
canverter
prollure

Throttle

pre
ur

AT448

Fir
AT
15
Oil
Pr
re
Circuit
D
m
D

rang
2nd

g
ar

AT15

Page 269 of 548


D3
ran

3rd
g
ar

Oi
I

pump

1

t

Torque
J

C
onYlrt
r

I
i

t
t

Pressure

reQula
or

Ya
lye

L
i
ns

pressure

Goyernor

pressure
Automatic
Transmission

Front

clurch
Rlar

clutch
Brake

bond
Low

and

rever
brake

0

thBond
L
B
so

J
1

1

1

lt

r
T

tr
Throttle

pressure

t

t

I

@

t

Governor

pr
au
r

Torque
canYlr
er

pr
ssure

rIA
Throttle

pressure

AT449

Fill
AT
17
Oil

Pro
ure
Circuit

Diagram

D3
range
3rd

gear

AT
17

Page 276 of 548


X

F
1

2

dll
U
Sflift
lllvI

21

I

S
nd

lock

6

Ir

II

P

UX
6

I
Mo
ol

f

L
t

u
uu
u
u

I

f5

LI

P
OI

I
Go
o

fo
d
P
I

ren
e
2nd
eer

Torqul
con
rter

Oil

pump

Oil

tool

RIAr
Ivbri
cor
ion

D

Orain

fa
hi

Front

lubrici
lti

0
0
0

1
I

tU

x

j
Pr

l

UQU
010r

Yol

u

1
Automatic
Transmission

Front

lulch
Riot

x

l

N
r

N
N

I
I

i
l
I
18
16

ahl

J
@

Vacuum

Huottl

Vol

if

J
II

Throttl

drain

yol
l

II
@2ft
3rd
Shiff

101
1

iii

1J

g
2nd

3rd

timino

101
11
8

Goy
rnor

prlUUAI

Torque
Cony
tar

pr
r

Th
toni

pt
ure
Slcondor

governor
vol
1
Primo

00
vlrnor
va

AT461

Fig
AT
21
Oil
Pr
Circuit

Dwgrom

12
ro

2nd
ear

AT
24

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