TWO
SPEED
AUTOMATIC
TRANSMISSION
7F-37
Co
Check modulator valve and bore in
case
for
freedom of movement.
d.
Check freedom of boost valve in
front
pump
regulator.
2.
Valve body bolts loose. Torque specification Is
10 lb. ft.
3. Low oil
level.
PRESSURE CHECKS
Pressure
checks
are a ^sefal part of trouble diag-
nosis. The
pressure
tap for checking mainline
pres-
sure
is located above the oil pan
rail
on the
right
side of the transmission and to the
rear
of the low
servo.
Tests
can be
made
without
driving
the vehicle by
simply
raising
rear
wheels 3-5 inches
from
floor
on
jack
stands.
With
pressure
gauge
installed, perform
following
preliminary
steps:
1.
Establish
pressure
gauge
indicator
needle
rest
position
at zero
pressure.
2.
Thoroughly warm up transmission.
3. Check transmission oil
level.
4.
Make
sure
vacuum line connections are
tight.
5. Check linkage adjustment.
Mainline
pressure
will
vary
from
one transmission
to
another but
following
statements
apply in general.
Line
pressure
should
increase
as engine mani-
fold
vacuum
decreases,
at a constant
speed.
Line
pressure
should
decrease
as car
speed
increases,
at a constant engine
manifold
vac-
uum
(for example, about 13 psi between 40-60
mph).
Reverse
pressure
should be about 85 psi at idle
to
over 200 psi at stall (wide open throttle
with
brakes
on).
NOTE:
Do not
operate
at
wide
open
throttle
with
brakes
on
longer
than it is
necessary
to
obtain
a
gauge
reading.
MAXIMUM
LINE
PRESSURE
Maximum
line
pressure
checks
are to be
made
in
garage
bay
with
vacuum modulator line disconnected
and plugged and
with
engine
speed
set at 1000 rpm.
See figure 7F-111 for
pressures.
MINIMUM
LINE
PRESSURE
Minimum
line
pressure
checks
are to be
made
while
road testing the car
with
the vacuum modulator
line
connected. Checks are to be
made
as
follows:
1.
Park, Neutral and
Drive
- 56 psi.
Drive
-
coast
at 20-40 mph
with
foot off throttle. Neutral
and Park - check at 1000 rpm.
2.
Low - 92 psi;
coast
at 20-40 mph
with
foot off
throttle.
3.
Reverse
- 84 psi;
coast
with
foot off throttle.
MODEL
LA,
LB,
LF,
LG
LD,
LH
MA,
MB
MC
Barometric
D &
L
D
& L
D &
L
D
& L
Altitude
Pressure
±
4 psi
±
4 psi
±
4 psi
±
4 psi
Sea Level
29.92
155
147
165
163
2,000 ft.
27.82
147
140
157
155
5,000 ft.
24.89
134
128
144
144
Reverse
Line
Pressure
should exceed
Drive
Pressure
by at
least
60 psi
Fig.
7F-111
Maximum
Line
Pressure
To Next Page
Loading...
