Pontiac FIREBIRD 1972 Service Manual page 858

SECTION 7C
FOUR SPEED SAGINAW TRANSMISSION
CONTENTS OF THIS SECTION
Trouble Diagnosis
....................................................
7C-1
General Description
................................................
7C-1
Periodic Service Recommendations
........................
7C-1
On Car Adjustments
Floor Shift and Back Drive Linkage
..................
7C-2
Minor Repairs
Rear Extension Oil Seal
......................................
7C-3
Rear Extension Oil Seal and Bushing
................
7C-3
Transmission Case Cover
....................................
7C-5
Major Repairs
Transmission, Remove
........................................
7C-6
Transmission, Disassemble
..................................
7C-6
Cleaning and Inspection
......................................
7C-8
Transmission, Assemble
......................................
7C-9
Transmission, Install
..........................................
7C- 11
Specifications
Transmission Identification
..............................
7C- 12
........................................................
Gear Ratios 7C- 12
............................................................
Lubricant 7C- 12
...............................................................
Torque 7C- 12
..........................................................
Special Tools 7C- 12
TROUBLE DIAGNOSIS
Refer to Section 7A.
GENERAL DESCRIPTION
The Saginaw four-speed transmission is an optional floor
shift, manual transmission used with the 350 cu. in., two
barrel carburetor-equipped engine on A and F Series mod-
els. It has all forward gears fully synchronized with a
constant mesh reverse idler (Fig. 7C-1).
The main drive gear is supported by a ball bearing at the
front end of the transmission case and is piloted at its front
end in an oil impregnated bushing mounted in the engine
crankshaft. The front end of the mainshaft is piloted in a
row of roller bearings set into the hollow end of the main
drive gear and the rear end is carried by a ball bearing
mounted in the front of the extension housing.
The countergear is carried on a single row of rollers at
both ends while thrust is taken on thrust washers located
between the ends of the gear and the thrust bosses in the
case. An anti-rattle plate assembly at the front of the
countergear provides a constant spring tension between
the counter and clutch gears to reduce torsional vibra-
tions.
The synchronizer assemblies consist of a clutch hub, slid-
ing sleeve, three keys, two springs and are retained as an
assembly on the main shaft by a snap ring.
A great deal of similarity and interchangeability now ex-
ists between the new 3 and 4-speed Saginaw transmissions.
The cover on the new four-speed transmission is located
on the left-hand side of the case. It is similar to the three-
speed cover with the addition of a reverse shifter shaft
assembly, detent ball and detent spring.
A transmission controlled spark (TCS) switch is screwed
into the boss of the 3rd and 4th shifter shaft opening of
the transmission side cover. This TCS switch is closed in
all but high gear, grounding an electrical circuit from the
distributor and engine thermo-switch through a solenoid
valve. This closing, or grounding, of the TCS switch will
retard the spark.
The reverse idler gear is held in constant mesh with the
When the transmission is shifted into high gear, the pivot-
1st and 2nd synchronizer gear regardless of its position.
ing of the 3rd and 4th shifter shaft will cause the TCS
The idler gear is carried on a bushing finish bored in place
'
switch to open, so that the transmission will no longer
and rotates on a short idler shaft retained by a Woodruff
affect the vacuum advance of the distributor. See Section
key. 6D for further details.
PERIODIC SERVICE RECOMMENDATIONS
Refer to Section 7A.