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MANUAL TRANSMISSIONS
78-1
SECTION 7B
MANUAL TRANSMISSIONS
CONTENTS OF THIS SECTION
General Description
..................................................................................................
7B- 1
3-Speed 76mm Muncie
.....................................................................................
7B-1
4-Speed 76mm Muncie
.......................................................................................
7B-1
4-Speed 82mm Borg-Warner
................................................................................
7B-6
5-Speed 77mm Borg-Warner
................................................................................
7B-9
Diagnosis
............................................................................................................
7B-1 1
Maintenance and Adjustments
.................................................................................
7B- 16
On Car-Service
......................................................................................................
7B-22
...............................................................................................................
Unit Repair
7B-27
.........................................................................................
3-Speed 76mm Muncie
7B-27
4-Speed 76mm Muncie
.........................................................................................
7B-3 1
4-Speed 82mm Borg-Warner
...............................................................................
7B-38
5-Speed 77mm Borg-Warner
................................................................................
7B-45
Specifications
.............................................................................................................
7B-60
Special Tools
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7B-61
GENERAL DESCRIPTION
3-SPEED 7 6 M M LT. DUTY MUNCIE TRANSMISSION
$-SPEED 7 6 M M LT. DUTY
These
transmissions
are
representative
of
a
synchronized,
constant-mesh
design.
Fundamental
components of these units are the case, which houses the
gears and shaft; the control cover, which houses the shifter
mechanism; and the various shafts and gears. The input shaft
has an integral main drive gear and rotates with the clutch
driven plate; that is, the shaft rotates all the time the clutch
is engaged and the engine is running. The input shaft is
supported in the case by a ball bearing and at the front end
by an oil impregnated bushing mounted in the engine
crankshaft. The drive gear is in constant mesh with the
countershaft drive gear. Since all gears in the countershaft
cluster are integral to the shaft, they also rotate at the time
the clutch is engaged. The countergear is carried on roller
bearings at both ends and thrust is absorbed by thrust washers
located between the countergear and thrust bosses in the case.
An anti-lash plate assembly at the front face of the
countergear provides a constant spring tension between the
countergear and the main drive gear to reduce torsional
vibrations. The transmission mainshaft is held in line with the
input shaft by a pilot bearing at its front end, which allows
it to rotate or come to rest independently of the input shaft.
MUNCIE TRANSMISSION
Its carried at the rear by a ball bearing mounted in the front
face of the extension housing.
Helical gears are incorporated throughout, (except
reverse gear on the four speed 76mm unit which uses a spur
gear design.) The mainshaft gears are free to rotate
independently on the mainshaft and are in constant mesh
with the countershaft gears. The reverse idler gear is carried
on a bushing finish bored in place and thrust is taken on the
thrust bosses of the case.
The transmissions are fully synchronized in all forward
speeds; however, reverse gear is not. The synchronizer
assemblies consist of a hub, sleeve, two key springs and three
synchronizer keys. The synchronizer hubs are splined to the
mainshaft and retained by snap rings. These assemblies
permit
gears to be
selected without
clashing, by
synchronizing the speeds of mating parts before they engage.
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