Buick LeSabre 1965 Service Manual page 226

5 - 1 2 DESCRIPTION & OPERATION
SUPER TURBINE "300'
sensitive modulating oil pressure
that increases up to a point with
output shaft or car speed.
6. Valve Body
The valve body assemblies are
bolted to the bottom of the trans-
mission case and are accessible
for service by removing the oil
pan. The main valve body assem-
bly consists of manual control
valve, stator and detent valve,
shift valve, modulator limit valve,
and high speed downshift timing
valve. The stator valve body con-
sists of a stator control valve.
5 - 4 MECHANICAL
OPERATION OF
SUPER TURBINE
" 3 0 0 " AUTOMATIC
TRANSMISSION
1. Operation of Components
in Drive Range
With the manual control lever in
Drive range, the transmission is
s t a r t e d automatically in Low
range. The forward clutch is re-
leased and the low band is applied
to the outside diameter of the
forward clutch drum. With the
low band applied, the low sun gear
and flange assembly are held sta-
tionary. Drive then is from the
converter through the input shaft
to the input sun gear in the plane-
tary gear set. The input sun gear
drives the long planet pinions
which in turn drive the short
planet pinions. The short pinions
are in mesh with the low sun
gear. With the low sun gear held
stationary by the low band appli-
cation, the short pinions will walk
around the low sun gear. As they
walk around the sun gear, they
carry with them the planet car-
rier and the output shaft to which
they are attached, at a reduction
of 1.76 to 1.
The upshift into Drive range is
dependent upon car speed and
throttle opening. When the shift
occurs, the low band is released
and the forward clutch is applied.
Application of the forward clutch
locks the planetary system caus-
ing it to rotate as a unit. With
the clutch applied, the clutch hub
which is splined to the input shaft
is locked to the low sun gear and
flange a s s e m b l y through the
clutch plates. The low sun gear is
meshed to the short pinions, the
short pinions are meshed with the
long pinions, and the long pinions
are meshed with the input sun
gear; the sun gear is also splined
to the input shaft. Since both the
low sun gear and input sun gear
are now locked to the input shaft,
the entire planetary unit will re-
volve at input shaft speed. See
Figure 5-10.
2. Operation of Components
in Manual or Automatic
Low Range
In Low range, the forward clutch
is released and the low band is
applied to the outside diameter of
the forward clutch drum. With
the low band applied, the low sun
gear and flange assembly is held
stationary. Drive then is from the
converter through the input shaft
to the input sun gear in the plane-
tary gear set. The input sun gear
drives the long planet pinions
which are in mesh with the low
sun gear. Since the low sun gear
is held stationary with the low
band applied, the short pinions
walk around the low sun gear,
and as they walk around the sun
gear, they carry with them the
planet carrier and the output shaft
to which they are attached at a
reduction of 1.76 to 1. See Figure
5-11.
3. Operation of Components
in Reverse Range
When the manual control lever is
in Reverse position, the forward
clutch and low band are released,
and the reverse clutch is applied,
holding the ring gear stationary.
Drive is through the input shaft
and input sun gear to the long
pinions and then to the short pin-
ions. The short pinions mesh with
the reverse ring gear which is
held stationary by the reverse
clutch. The short pinions walk
around the inside of the ring gear
in a reverse direction, turning
the output shaft to which they are
attached at a reduction of 1.76 to
1. See Figure 5-12.
4. Operation of Components
in Neutral
With the shift control lever in
Neutral position, the output shaft
remains stationary. The clutches
and low band are released; there-
fore, there is no reaction member
to provide positive drive. All
gears are free to spin around
their own axis, and no motion is
imparted to the planet carrier.
See Figure 5-13.
5. Operation of Components
in Park
In Park, all reaction members
are released as in Neutral. A
positive gear train lock is pro-
vided when the parking pawl is
engaged with the heavy teeth
spaced around the front face of
the planetary carrier. The link-
age is actuated by direct manual
action, but the parking pawl is
activated by spring action. If the
pawl is in line with a tooth of the
planet c a r r i e r , rather than a
space between teeth, the linkage
remains in the park position with
the spring holding p r e s s u r e
against the pawl. Slight rotation
of the planet carrier will immedi-
ately seat the pawl and lock the
output shaft to the case. See
Figure 5-13.