Chevrolet 30 Series 1967 Service Manual page 424

CLUTCHES AND TRANSMISSIONS 7-38
General Description......................................................... .... 7-38
Maintenance and Adjustments
Oil Level C h e c k ......................................................... .... 7-38
Periodic Oil C h a n g e ................................................... .... 7-38
Periodic Low Band A d ju stm e n t................................. .... 7-39
Manual Shift Linkage Check and A d j u s t ............... .... 7-39
Throttle Valve L in k a g e .......................................... .... 7-40
Neutral Safety S w itch ............................................. .... 7-40
Throttle Return Check Valve (Dashpot)
Component Parts R eplacem en t....................................... .... 7-40
Transmission R e p lacem en t....................................... .... 7-40
Other Service O p erations................................................ .... 7-41
D ia g n o s is .................................... .. ..................................... 7-41
The case and converter housing of the two speed alumi­
num Powerglide Transmission is a single case aluminum
unit. When the manual control is placed in the drive po­
sition, the transmission automatically shifts to low gear
for initial vehicle movement. As the car gains speed and
depending on load and throttle position, an automatic shift
is made to high gear. A forced downshift feature pro­
vides a passing gear by returning the transmission to low
range.
The oil pump assembly is a conventional gear type and
the oil pump housing is of the large diameter type acting
as the front bulkhead of the transmission.
converter is a conventional three element welded design
bolted to the engine flywheel which drives through a two-
speed planetary gearset.
typical of the designs used in this type transmission. The
aluminum Powerglide uses an output shaft mounted gov­
OIL LEVEL CHECK
The transmission oil level should be checked periodi­
cally as recommended in Section 0.
only when level is on or below the "ADD" mark on the dip
stick with oil hot or at operating temperature.
level dip stick is located at the right rear of the engine
compartment. Fill with oil specified in Section 0.
In order to check oil level accurately, the engine should
be idled with the transmission oil hot and the control
lever in neutral (N) position.
It is important that the oil level be maintained no
higher than the "FU LL" mark on the transmission oil
level gauge. DO NOT OVERFILL, for when the oil level
is at the full mark on the dip stick, it is just slightly be­
low the planetary gear unit. If additional oil is added,
bringing the oil level above the full mark, the planetary
unit will run in the oil, foaming and aerating the oil. This
aerated oil carried through the various oil pressure pas­
sages (low servo, reverse servo, clutch apply, converter,
etc.) may cause malfunction of the transmission assem­
bly, resulting in cavitation noise in the converter and
improper band or clutch application. Overheating may
also occur.
If the transmission is found consistently low on oil, a
ALUMINUM POWERGLIDE
Page
....................................... .... 7-38
............... .... 7-40
GENERAL DESCRIPTION
The torque
The high clutch assembly is
MAINTENANCE AND ADJUSTMENTS
Oil should be added
The oil
INDEX
Warming Up T ransm ission ..........................................
Shop Warm U p .........................................................
Road Warm Up
Checking Fluid Level and C o n d itio n ...........................
Manual L in k a g e............................................................
Oil L e a k s .....................................................................
Basic Pressure Checks
Wide Open Throttle Upshift Pressure Check . . . .
Idle Pressure in Drive R a n g e .................................
Manual "Low " Range Pressure C h e c k ..................
Drive Range Overrun (Coast) P r e s s u r e ..................
Powerglide Shift P o in ts................................................
ernor which requires a hole through the output shaft.
The reverse clutch assembly is a multiple disc type
clutch. The steel plates are splined directly to the case
while the face plates are splined to the internal or ring
gear. The clutch piston operates within the rear portion
of the case. The internal diameter of the piston is sealed
to an integral hub portion of the case rear bulkhead. The
outside diameter is sealed to a machined portion of the
case. The piston is hydraulically applied and is released
by separate coil springs. The valve body assembly is
bolted to the bottom of the transmission case and is ac­
cessible for service by removing the oil pan assembly.
The valve body consists of an upper and lower body lo­
cated on either side of a transfer plate. The vacuum
modulator is located on the left rear face of the trans­
mission case. The modulator valve bore is located in the
upper valve body.
thorough inspection should be made to find and correct all
external oil leaks.
PERIODIC OIL CHANGE
The transmission oil should be changed periodically as
recommended in Section 0, and whenever transmission is
to be removed from the vehicle for repairs.
1. Run engine for one minute in neutral prior to
changing.
2. Be sure vehicle is level or raise from the rear only.
3. Remove the oil pan drain plug and allow oil to drain
thoroughly into a pan or can.
4. Replace drain plug and refill with approximately two
quarts of oil specified in Section 0.
NOTE: To refill the transmission, remove dip
stick from oil filler tube and refill transmission
with oil specified in Section 0 using filler tube
and funnel J-4264.
ranges at idle speed to fill all oil passages, the
engine should be run at 800-1000 rpm with the
transmission in Neutral until the oil warms up,
then add oil as required to raise the fluid level
to the full mark on the dip stick. Refill capacity
is approximately
......................................................
.............................................
Then, after shifting into all
qts.
2
CHEVROLET TRUCK SERVICE MANUAL
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