Paccar TX-8, Руководство оператора

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Automatic Transmission
Maintenance
An automatic transmission is a complex
and expensive vehicle component
requiring operational attention and proper
maintenance to ensure long-lasting
performance. This performance is
impacted greatly by the quality of its
lubricating fluid, which reduces friction
between its many parts, facilitates gear
shifting, and cools down the transmission
components.
The chief factor that affects the durability of
a lubricating fluid is temperature. When the
operating temperature of the transmission
increases, this fluid begins to break down,
degrading its lubricating properties.
Without proper lubrication, friction between
components increases, breaking them
down and building up sludge in the
transmission. This will eventually result in
transmission failure, requiring it to be
replaced.
A transmission's peak operating
temperature can be defined as its
maximum general operating temperature
and is determined by how the transmission
is used. The "hard use" associated with
some truck applications — such as the
stop-and-go conditions of CITY DELIVERY,
or the hauling of heavy loads and trailer
use associated with many VOCATIONAL
and highway applications — will increase
this peak operating temperature, and
hasten the break down of the transmission
lubricant.
Therefore, it is essential that proper
lubrication maintenance is performed for
the operational temperature specific for
your transmission use.
Operational temperature data for this
transmission can be collected by your
PACCAR Powertrain distributor technician
early in the truck's life (collected during the
first 5,000 miles of operation (see First
3,000 – 5,000 mi interval)). The value of
this data will depend on whether this early
temperature data – which is based on truck
application – is representative of how the
vehicle will be used for the life of the truck.
NOTE
If vehicle application changes signifi-
cantly, the vehicle should be re-evalu-
ated for a new peak operational tem-
perature, and if necessary, observe
the maintenance intervals associated
with the new peak temperature.
Once the peak operating temperature is
known, the appropriate maintenance tables
can be observed. If the peak operating
temperature has not been determined,
assume the 95ºC peak operating
temperature intervals.
Unlike engine oil, transmission fluid serves
as both a lubricant and a hydraulic fluid.
The hydraulic pressure needed to shift
gears smoothly (and avoid gear slippage)
requires that the operator maintain
transmission fluid in the proper range (see
How to Check Transmission Fluid on page
23). The operator should check their
transmission fluid regularly, required as
part of their weekly checks (see Weekly
Checks in your chassis operator's manual).
MAINTENANCE - Automatic Transmission Maintenance
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