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TRANSAXLE - TA65 Star
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3. GENERAL DESCRIPTION
TA65 star is similar transmission as current TA65 as
regards the architecture of input shaft, lay shaft and
differential final drive, bearings and oil seals. The
transmission TA65* provides five forward speeds
and one reverse speed by means of three
synchronizers and input shaft, lay shaft and reverse
idler shaft and differential. All forward gears are in
constant mesh engaged through synchronizers and
reverse gear uses a sliding idler gear arrangement.
All the synchronizers are mounted on lay shaft and
engaged with gears on lay shaft. The lay shaft turns
the final drive gear and differential assembly,
thereby turning the front drive shafts which are
attached to the front wheels.
Movement of gear shift lever / knob is transmitted
through gear shift cables and shift /select levers on
transmission to the selector shifting finger. This is
further transmitted through shifter dogs and shifter
forks to the shifter sleeves and synchronizers.
Interlock piece is provided to prevent double
engagement of gears. Inhibitor is provided to block
direct shift from 5th gear to Reverse gear which
guides the shift lever towards 4th gear. Central
detent is provided for distinct position of gears about
neutral position
CHANGES AND BENEFITS OVER TA65:
The major areas of change and benefits over TA65
are:
1. The internal and external gear shifting
mechanism and arrangement. TA65 star
employees cable shift in place of current rod shift
for TA65.
The advantages of cable shift over rod shift are:
Better end stop feel.
No gear shift lever vibrations. No gear lever
rocking
Ease of routing / packaging, better
serviceability.
2. Twin cone carbon lined synchronizers for first
and second gears to replace single cone brass
synchronizers. Benefits are improved shift
smoothness, reduction in shift efforts and
enhanced life of synchro cones.
3. Deletion of intermediate plate and its integration
into housing front half. This has improved the
housing rigidity and accuracy of gear train
positioning thus helping reduction in noise level.
4. The selection / shifting bracket in TA65 is
replaced by integrating it in to one single unit
called ‘Assembly Top cover’ which is placed at
top of transmission.
5. Features of top cover are:
The shifting components can be serviced
by removing the top cover alone.
The selector shifter shaft seal is located on
top against at bottom in TA65.
The top cover is provided with central
detent to replace individual detents of
shifter shafts. A well optimized cam profile
on shifter finger, gives good shift feel and
precision.
6. TA65 star front half housing is 10mm wider than
of TA65 to accommodate increased inertia
flywheel to reduce marching noise. Housings are
strengthened as compared to TA65 by additional
ribs.
7. Rear cover rubber seal is replaced by liquid
gasket. 8 No’s of bolts are used to mount the rear
cover in place of 3 bolts in TA65.
8. The reverse light switch is shifted to top side of
transmission, to reduce failures of oil dipped
switch in TA65.
Mechanical Speedo (pinion and gear arrangement)
is replaced by contact less Speedo (A sensor and a
toothed wheel). This is to improve reliability of
Speedo mechanism and to reduce complexity in
assembling transaxles.