1977 DATSUN PICK-UP service

DATSUN
PICK
UP

MODEL
620
SERIES

I
NISSAN

I

NISSAN
MOTOR
CO
LTD

TOKYO
JAPAN
SECTION
AT

j

AUTOMATIC
L

TRANSMlsSIO
N

I

I

DESCRIPTION

HYDRAULIC

CONTROL
SYSTEM

REMOVAL
AND
INSTALLATION

MAJOR
REPAIR

OPERATION

TROUBLLDIAGNOSES
AND

ADJUSTMENT

SERVICE
DATA
AND

SPECIFICATIONS

I
SPECIAL
SERVICE

TOOLS
At
2

AT
4

AT

33

AT
36

AHD

AT

59

AT

62

The
model
3N7l
B
automatic

trans

mission
is

a

fully
automatic

unit
con

sisting
primarily
of
3
element

hydrau

lic

torque
converter
and

two

planetary

gear
sets
Two

multiple
disc
clutches
a

multiple
disc
brake
a
band
brake
and

a
one

way

sprag
clutch

provide
the

friction
elements

required
to
obtain

the
desir
d
function
of
lhe
two

plane

tary
gear
sets

The

two

planetary
gear
sets

give

three
forward
ratios

and
one
reverse

Changing
of
the

gear
ratios
is

fully

automatic
in
relation
to
vehicle

speed

and

engine
torque
input
V

chide

speed

and

engine
manifold
vacuum

signals

are

constantly
fed
to
the

transmission

to

provide
the

proper
gear
ralio
for

maximum

efficiency
and

performance

at
all
throttle

openings

The
model
3N71
B
has
six

selector

1

9sition
LP
R

N
D
2
1

I

Park

position
positively
locks

the

output
shaft
to

the
transmission

case

by
means
of
a

locking

pawl
to

prevent
the
vehicle
from

rolling
in

either
direction

This

position
should
be

selected

whenever
the
driver
leaves
Ihe
vehicle

Thc

engine

may
be
slarted
in
Park

position

R
Reverse

range
enables
the

vehicle
to
be

operated
in

a
reverse

direction

N
Neutral

position
enables
the

engine
to

be
started
and
run

without

driving
the
vehicle

0
Drive

range
is
used

for
all

normal

driving
conditions

Drive

range
has
three

gear
ratios

from
the

starting
ratio

to
direct
drive
Automatic
Transmission

DESCRIPTION

2

2

range
provides

performance

for

driving
on

slippery
surfaces

2

range
can
also
be
used
for

engine

braking

2

range
can
be
selected
at

any

vehicle

speed
and

prevents
the
trans

mission
from

shifting
out
of

second

gear

I
I

range
can
be

selected
at

any
vehicle

speed
and
the
transmission

will
shift
to

second

gear
and
remain
in

second
until
v

hicle

speed
is
reduced

10

approximately
40
to
50

kmfh
25

to
30
MPH

I

range
position
prevents
the

transmission
from

shifting
out
of
low

gear
This
is

particularly
beneficial
for

maintaining
maximum

engin
braking

when

continuous
low

gear
operation
is

desirable

The

torque
converter

assembly
is
of

welded

construction
and
can

nOlbe

disassembled

for
service

FLUID
RECOMMENDATION

Use
automatic
transmission

fluid

having
DEXRON
identifications

only
in
the
3N71
B

automatic
transmis

sion

IDENTIFICATioN
NUMBER

Stamped

position

The

plate
is

attached
to
the

right

hand

side
of
transmission
case

as

shown
io

Figure
AT

I

AT
2
AT344

Fig
AT
I

Identification
number

Identification

of
number

Arrangements

See
below

Model
code

JAPAN

AUTOMATIC

0J
TRANSMISSION
CO
LTD

I
MODEL
X2402

I

J
I
NO

4912345

I

Unit
number

Number

designation

4
9

I

234
5

L

Serial

production

number
for

the
month

Month
of

production

X

Oct
Y

Nov
Z
Dec

last

figure
denoting

the

year
A
D

Starter

should
be

brought
into

op

eration

only
when
selector

lever
is
in

P

and
N

positions
it

should
not

be
started

when
lever
is
in
D
2

I

and
R

positions

Back

up
lamp
should
also

light

when

selector
lever
is

placed
in

R

position

S
After

converter
is
installed

rotate

10

Check
level
of
oil
in
transmis

crankshaft
several
turns
and
check

to

be
sure
that
transmission

rotates

freely
sion

For
detailed

procedure
see

page

AT48

without

binding

6
Pour

recommended
automatic
II

Move
selector
lever

through
aU

positions
to
be

sure
that
transmission

transmission

fluid

up
to
correct
level

operates
correctly

through
oil

charge
pipe

verter
to
transmission
measure

dis

With
hand

brake

applied
rotate

tan
A

to
be
certain

that

they
are
7

Connect
manual
lever
to
shift

engine
at

idling
Without

disturbing

correctly
mbi
d

S
F
rod

Opeiationsliould
oecaTrie
f
bue

the
above

sclUng
ffiovTSelector
lever

AT

50
with

manual
and
selector
levers
in

through
N

to
D
to
2

to
I

Distance
A
N

and
to
R
A

slight
shock
should
be

More
than
21

5
mm
0
846
in
8
Connect

inhibitor
switch
wires

felt

by
hand

gripping
selector

each

time
transmission
is
shifted
Automatic
Transmission

4
Bolt
converter
to
drive

plate

Note

Align
chalk
marks

painted
a

cross
both

parts
during
disas

sembling

processes

AT116

Fig
AT
49

Torque
converter

aligning
cu
t

3
When

connecting

torque
can

A

ATl17
Notes

a
Refer
to

covering
topic

under

Checking
and

adjusting

inhibitor
switch
n

on

page

AT
49

b

Inspect
and

adjust
switch
as

above
whenever
it
has
to

be

removed
for
service

Fig
AT
50

Installing

torque
converter
9
Check
inhibitor
switch
for

op

eration

AT
34
Note

See

page
AT

49
for

checking

engine
idling

12

Check

to
be

sure
that
line

pres

sure
is

correct
To
do
this

refer
to

relative

topic
under

Testing
line

pres

sure
on

page
AT

52

13

Perform

stall

test
as

per
the

instructions

on

page
AT

50

Automatic

Transmission

MAJOR

REPAIR

OPERATION

SERVICE
NOTICE
FOR

DISASSEMBLY

AND

ASSEMBLY

TORQUE
CONVERTER

INSPECTION

TRANSMISSION

DISASSEMBL
Y

INSPECTION

ASSEMBL
Y

SERVICE
NOTICE

FOR
DISASSEMBLY

AND
ASSEMBLY

I
It

is
advisable

that

repair
opera

tions
be

carried
out
in
a

dust

proof

room

2
Due

to
the
differences
of
the

engine
capacities
the

specifications
of

component

parts
for

each
model
s

transmission

may
be
different

They

do
however
have

common

adjust

ment

and

repair

procedures
as
well
as

cleaning
and

inspection

procedures

outlined
hereinafter

3

During
repair
operations
refer
to

Service
Data

and

Specifications
see

tion
for

the
correct

parts
for
each

model

4

Before

removing
any
of

subas

semblies

thoroughly
clean
the
outside

of
the

transmission
to

prevent
dirt

from

entering
the
mechanical

parts

5

Do
not
use
a
waste

rag
Use
a

nylon
or

paper
cloth

6
After

disassembling
wash
all
dis

assembled

parts
and
examine
them
to

see
if
there
are

any
worn

damaged
or

defective

parts
and
how

they
are

affected
Refer
to

Service
Data
for

the

extent
of

damage
that

justifies

replacement

7

As
a
rule

packings
seals
and

similar

parts
once
disassembled
should

be

replaced
with
new
ones

TORQUE

CONVERTER

The

torque
converter
is

a
welded

construction
and

can
not
be
disas

sembled
CONTENTS

AT

36

AT

36

AT

36

AT

36

AT

36

AT
38

AT

38
COMPONENT
PARTS

FRONT

CLUTCH

REAR

CLUTCH

LOW
REVERSE
BRAKE

SERVO

PISTON

GOVERNOR

OIL

PUMP

PLANETARY

CARRIER

CONTROL

VALVE
AT

40

AT
40

AT
41

AT
42

AT
42

AT
43

AT
43

AT
44

AT

44

INSPECTION
2

Remove
bolts

securing
converter

1

Check

torque
convertf

for

any
housing
to
transmission

case
Remove

sign
of

damage

bending
oil
leak

or
torque
converter

deformation

If

necessary
replace
3
Remove

speedometer
pinion

2

Remove
rust
from

pilots
and
sleeve

bolt
Withdraw

pinion

bosses

completely
4

Remove
downshift
solenoid
and

If

torque
converter
oil
is

fouled

or
vacuum

diaphragm
Do

not
leave
dia

contaminated
due
to
burnt
clutch

phragm
rod
at
this

stage
of
disas

flush
the

torque
converter
as
follows
sembly
Rod
is

assembled
in

top
of

vacuum

diaphragm
See

Figure

I
Drain
oil
in

torque
converter

AT

53

2
Pour

non
lead

gasoline
or

kero

sene
into

torque
converter

approxi

mately
0
5
liter

I
U
S

pt
U

Imp

pt

3

Blow
air

into

torque
converter

and

flush
and
drain

out

gasoline

4
Fill

torque
converter
with

torque
converter
oil

approximately

0
5
liter
I

V
S

pt
U

Imp
pt

5

Again
blow
air
into

torque
con

verter
and
drain

torque
converter
oil

TRANSMISSION

DISASSEMBLY

I

Drain
oil
from
the

end
of
rear

extension

Mount
transmission
on

Transmission
Case

Stand
ST07870000

or
ST07860000
Remove

oil

pan
See

Figure
AT
52

AT118

Fig
AT

52

Removing
oil

pan

AT

36
Fig
AT
53
Down

hilt
olenoid
and

vacuum

dilJphragm

5

Remove

bolts
which

hold
valve

body
to
transmission

case
See

Figure

AT
54

Fig
AT
54

Removing
valve

body

6
Loosen
lock
nut

@
on

piston

stem

D
as
shown
in

Figure
AT

55

Then

tighten

piston
stem
in

order
to

prevent
front
clutch

drum
from

falling

when
oil

pump
is
withdrawn

Automatic

Transmission

L
1
r

E
5

Eo

1

20

mm
l

AT148

3

0
079
in

Cut
off
hatched

portion

Fig
AT

SO

Modifying
coil

spring

compres
or

3
Take
out

spring
retainer

f
and

spring
@
See

Figure
AT
78

4

Blowout

piston
by
directing
a

jet

of
air
inlO
hole
in

clutch
drum
See

Figure
A
T
8l

AT149

Fig
AT
81

Blowing
out

piston

Inspection

I

Check
for

signs
of
wear

or
dam

age
to

clutch
drive

plate
facing
If

found
worn
or

damaged
excessively

discard
See
Service
Data
for
limits

2

Check
for
wear
on

snap
ring
and

for
weakened
or
broken
coil

spring

If

necessary
replace
with

new
ones

Spring
retainer
should
also
be
in

spected
for

warpage

Assembly

I

Assembly
is
in

reverse
the
order

of

disassembly

Dip
all

parts
in

clean

automatic

transmission
fluid
before

installing

2
Line

up
driven

plates
so
that

stripped
arcs
are

properly
aligned

paying
particular
attention
to
the
loca

tion
of

oil
holes
in
clutch
drum
See

Figure
AT

82

Note
The
number
of
drive
and
driven

plates
varies
with
the

type
of
vehi

cle
For
detailed
information

see

Service
Data

Specifications
AT150

Lub

ication
hole

Fig
AT

82

Inserting
clutch

plate

3
After
clutch
is
assembled

make

sure
that

clearance
between

snap

ring

CD
and

retaining
plate
@
is
held

within

specified
limits
If

necessary

try
with

other

plates

having
different

thickness

until

correct
clearance
is

obtained
See

Figure
AT
83

Specified
clearance

I
6
to
1
8

mm

0
063
to
0

071
in

Available

retaining

plate

Thickness
mm
in

10
6
0417

10
8
0425

11

0
0
433

11
2
0441

II
4

0
449

11
6

0457

AT151

Fig
AT
83

Measuring
ring
to

plate

clearance

4

Testing
front
clutch

With
front
clutch
assembled
on
oil

pump
cover
direct
a

jet
of
air
into

hole
in

clutch
drum
See

Figure

AT
84

AT
41
Fig
AT

B4

Testing
front
clutch

REAR
CLUTCH

Disassembly

AT153

1
Rear

clutch
drum

2
Front

clutch

piston

3

Snap
ring

4

Retaining

plate

5
Drive

plate

Fig
A
T
85
Sectional

view

of

rear
clu
tch
6

Driven

plate

7

Dished

plate

8

Spring
retainer

9

Coil

spring

I

Take
out

snap
ring

@
retaining

plate

@
drive

plate

@
driven

plate

@
and

dished

plate

f
Same
tech

nique
can
be

applied
as
in

disas

sembling
front

clutch
See

Figure

AT
85

2
Remove

snap
ring
from

coil

spring
retainer
See

Figure
AT
86

ST2532001

Xf

Fig
AT
86

Remolling
snap
ring

3
Blowout

piston
by
directing
a

jet

of

air
into

hole
in

clutch
drum
See

Figure
AT

87

AT155
V

i

J
i

j

Fig
AT
87

Blowing
out

piston
Automatic
Transmission

1

w

Ai

I

i
1

i

3
j

P2

0

AT157

Fig
A
T
89

Testing
rear
C
U
tch

Inspectl

ioW
S
REVERSE
BRAKE

Refer
to

page
AT41
for

Inspection

of
Front
Clutch

Assembly

Assemble
in

reverse
the
order
of

disassembly
Dip
all

parts
in
clean

automatic
transmission
fluid
before

assembling
Note

that
the
number
of

drive
and
driven

plates
varies
with

type

of
vehicle
F
or
details
refer
to
Serv

ice
Data

Specifications

I

After
rear
clutch
is
assembled

check
to
be
sure
that
clearance
be

tween

snap
ring
D
and

retaining

plate

l
is
held
within

prescribed
toler

ances
See

Figure
AT
88

Specified
clearance

1

0
to
1
5
rom

0
039
to
0
059
in

AT156

Fig
AT
SS

Measuring
ring
to

plate

clearance

2

Testing
rear
clutch

Install
rear
clutch

on
oil

pump

cover

Blow

compressed
air

into
oil
hole

to
test
for
defInite

clutch

operation
as

shown
in

Figure
AT
89
Disassembly

1
Fllow

steps
as
described
in

page

AT

36
for
Transmission

Disassembly

2
mow
out

piston
by

directing
a

jet

of
air
into
oil
hole
in
clutch

piston

Inspection

I
Check
drive

plate
facing
for

wear

or

damage
if

necessary
replace
Refer

to

Service
Data

Specifications
for

tolerances

2
Test

piston
return

spring
for

weakness
Discard
if
weakened

beyond

use

3

Replace
faulty

parts
with
new

ones

Assembly

I

After
low
reverse

piston
is

installed
assemble
thrust

spring
ring

retum

spring
thrust
washer
and

one

way
clutch
inner

race

Using

Hex
head
Extension

ST25570001

ST25570000

torque
hex
head
slot

ted
bolt
I
3
to
1

8

kg
m
9
to
13

ft
lb

2
Insert
dished

plate
driven

plate

drive

plate
and

retaining

plate
into

transmission
case
in

that
order
Install

sn

p
ring
to
secure
the
installation

Note

The
number
of
drive
and
driven

plates
wries
with

type
of
vehicle

For
detailed
information

refer
to

Service
Data

Specifications

AT42
3

Without

disturbiilg
the
above

setting
check

to
be

sure
that

clearance

between

snap
ring
and

retaining
plate

is

within

specified
limits
If

necessary

use
other

plates
of
different
thickness

until
correct

clearance
is

obtained

Specified
clearance

0
80
to
1

05
rom

0
0315
to
0

0413
in

4

Blow

compressed
air
into

oil
hole

in

low
reverse
brake
to
test
for

definite
brake

operation
as
shown
in

Figure
AT

90

Fig
AT
90

Testing
low

reverse

brake

SERVO
PISTON

Disassembly

I
Blowout

piston
by
directing
a

jet

of
air
into

hole
in

release
side
of

piston

2
Remove

servo

piston
return

spring

Inspection

Check

piston
for
wear

damage
or

other
faults
which

might
interfere
with

proper
brake

operation

v

r
0

111

Ll
7

J

I

AT159

Fig
AT
91

Removing
pi3ton

Fig
AT

96

Measuring
clearanc
Automatic
Transmission

6

u

ST255801JOO

AT264

Fig
AT

99

Measuring
runout

5

Tighten
pump
securing
bolts
to

specified

torque
0
6
to
0
8

kg
m
4

to
6
ft
Ib
Clearance

between
seal

ring
and

ring

groove
See

Figure
AT

97

Standarddearance
Note
Be
sure
to

a1ign
converter

0
04
io
0
16
mm
housing
securing
bolt

holes

0
0016
to
0
0063
in

6

Again
check
the

runout

of
oil

pump
cover

I
learance

Seal

ring

q

I

n
l

1
AT

5

Fig
AT
97

Measuring
clearance

Assembly

I

Set

up

pump
housing
with
inner

and
outer

pump
gears
on
it

2

Using
Oil

Pump

Assembling

Gauge
ST25580000

instail

pump

coverta

pump
housing
as
shown

in

Figure
A

T

98

ST

5

000

J
I

I

JL

AT166

Fig
AT
98

Centering
oil

pump

3

Temporarily
lighten

pump
secur

ing
bolts

4

Set

the
runout
of
oil

pump
cover

within

0
D7
mm
0
0028
in

total

indicator

reading
See

Figure
AT
99
Note

When
former
Oil

Pump
As

sembling

Gauge
is
to
be

used
make

a
screw
hole
in
side
of
it

PLANETARY
CARRIER

The

planetary
carrier

cannot
be

divided

into
its
individual

components

If

any
part
of

component
is

faulty

replace
the
carrier

as
a
unit

Inspection

Check
clearance

between

pinion

washer
and

planetary
carrier
with

a

feeler

See

Figure
AT

100

Standard
clearance

0
20
to

0
70
mm

0
0079
to
0
0276
in

Clearance

I

Jr

I
1

11

r

AT167

Fig
AT
100

Measuring
pinion
washer

to

ca
ier

clearance

AT
44
Replace
if

over
0

80
mm
0

0315

in

CONTROL
VALVE

The

control
valve

assembly
consists

of

many
preci
ion

parts
and

requir
s

extreme

care
when
it
has
to

be
reo

moved
and
serviced
It

is

good
practice

to

place
parts
in

a

part
rack
so
that

they
can
be

reassembled
in

valve

body

in

their

proper
positions
Added
care

should
also
be

exercised
to

prevent

springs
and
other
small

parts
from

being
scattered
and
lo
t

Before

assembly

dip
all

parts
in

clean
automatic
transmission

fluid
and

check
to
be
certain

that

they
are
free

of

lint
and
other
minute

particles
If

clutch
or
band
is

burnt
or
if
oil

becomes
fouled
the
control

valve
as

sembly
should

be

di
ssembled
and

flushed

Disassembly

I
Remove
bolts

and
nuts
which

retain
oil

trainer
Bolts

may
be
re

moved

with
a
screwdriver
but
it

is

recommended
that

Hexagon
Wrench

HT610oo800
and

Spinner
Handle

HT62350000
be
used
See

Figure

AT
101

HT61000800

Fig
AT
101

Disassembling
valve

body

2

Remove

attaching
bolts
With

bolts

removed
lower
valve

body

separate

plate
and

upper
valve

body

are
free
for

removal
See

Figure

AT
102

Note
Do
not
allow

orifice
check

vah
e

and
valve

spring
in
lower
valve

body
to
be
scattered
and
lost
when

removing
separate
plate

Automatic
Transmission

SERVICE
DATA
AND
SPECIFICATIONS

General

specifications
AfT

Torque
converter

Type

Stall

torque
ratio
Symmetrica13
element
I

stage

2

phase
torque
converter

2
0
I

Transmission

Type

Control
elements

Multiple
disc
clutch

Band
brake

Multiple
disc
brake

One

way
clutch

Gear
ratio

1st

2nd

3rd

Reverse
3

speed
forward
and

one
speed

reverse
with

planetary
gear
train

2

I

I

I

2

458

1458

1

000

2
182

Selector

positions
P
Park

R

Reverse

N
Neutral
Transmission
is

placed
in

neutral

Output
shaft
is

fIXed

Engine
can
be
started

Backward

running

Transmission
is
in

neutral

Engine
can
be

started

Up
or
downshifts

automatically
to

and
from
I

st
2nd
and

top

Fixed
at
2nd

Fixed
at
low

or
downshifts
from

2nd
o
Drive

2
2nd
lock

I
Lock

up

Oil

pump

Type
Internally
intermeshing
involute

gear
pump

Number
of

pump

Oil
Automatic
transmission
fluid

DEXRON

type

5
5

liters

SUU
s

qt
4Ulmp
qt

Approximately
2
7
liters

2UU
s

qt
2XIrnp

qt

in

torque
converter

Controlled

by
measuring
the

nega

tive

pressure
of
intake
manifold

and
the
revolution
of

output
shaft

Forced
lubrication

by
an
oil

pump

Water
cooled

by
a
circulation

type

auxiliary
cooler

located
at
the

radiator
Capacity

Hydraulic
control

system

Lubrication

system

Cooling
system

AT
59