Buick LeSabre 1965 Service Manual page 305

SUPER TURBINE " 4 0 0 '
DESCRIPTION & OPERATION 5 - 9 1
IS
I
k TO INT CL.
\ u
fl\ I N T C L . H M
n ^ ^ ^ 5 /
]
'
2
A C C U M
"
REV. OR LO
Figure 5-231
a. Rear Servo Function—Low
Range 1st Speed
On the 1-2 shift in Drive and L.2
Ranges it serves as an accumula-
tor for the intermediate clutch to
provide a smooth shift. See Fig-
ure 5-231.
b. Rear Servo Operation
in Drive—L
2
First Speed
In 1st gear Drive and L
2
Ranges,
1-2 accumulator oil is directed
to the rear servo accumulator
piston in preparation for the 1-2
shift. See Figure 5-232.
c. Rear Servo Operation—Drive
L
2
2nd Speed
Intermediate clutch apply oil is
directed to the rear servo ac-
TO INT CL.
REV. OR LO
TO INT CL.
r
REV. OR LO
Figure 5-233
cumulator p i s t o n , stroking the
piston against 1-2 accumulator
oil and the accumulator spring.
This action absorbs some inter-
mediate clutch apply oil and per-
mits the intermediate clutch to
apply at reduced pressure for a
s m o o t h 1-2 shift. See Figure
5-233.
d. Rear Servo Operation L
1
Range 1st Speed
Overrun engine braking in Lo
Range 1st gear is provided for by
the rear servo applying the band
to hold the reaction carrier from
clockwise rotation.
1-2 Accumulator oil is directed
to the accumulator piston which
attempts to prevent t h e servo
from applying. Lo Range oil di-
, 1
\
k T O I N T C L .
j [ \
INT CL.
H n
t i wr~M ' "
2 A C C U M -
k. mmmmmP I I
REV. OR LO
TO INT CL.
REV. OR LO
Figure 5-235
rected to the servo piston which
has the larger area, applies the
band. Because 1-2 accumulator
oil is present, the force applying
the band is lowered. This pro-
vides a smooth apply. See Figure
5-234.
e. Rear Servo Operation—
L
1
Range Second Speed
In second gear the rear band is
released. Intermediate clutch oil
is directed to the release side of
the servo piston which, with 1-2
accumulator oil, balances out the
L
1
Range oil on the apply side of
the servo piston and the servo
release spring strokes the servo
piston to the released position.
See Figure 5-235.
TO INT CL.
REV. OR LO
Figure 5-232 Figure 5-234
Figure 5-236