Importance Of Proper Fluid Level; Keeping Fluid Clean; Oil Contamination; Metal Particles - PREVOST H3-41 Maintenance Manual

SECTION 07: TRANSMISSION
Allison Transmission recommends you take the
following into consideration when selecting the
appropriate fluid type for your transmission:
 Fluids meeting specification TES295 are
preferred over TES389 fluids for use in all
4000 Product
applications.
 TES295 fluids are fully qualified for Severe
Duty and Extended Drain intervals.
 A TES295 fluid allows you to operate at a
lower ambient temperature than a TES389
type fluid.
 TES389 fluid is
requirement approved for use in 4000
Product Families transmissions.
 To extend the TES389 fluid drain intervals
beyond the recommended mileage or hours
change interval,
program.
When choosing a fluid type to use, consider
what the minimum fluid operating temperature of
the fluid will be based on the ambient
temperatures reached
location for the vehicle.
Transmission Fluid Operating Temperature Requirements
Minimum operating temperature
Fluid type
Celsius
TES295
TES389
CAUTION
Disregarding minimum fluid temperature limits
can result in transmission malfunction or
reduced transmission life.
NOTE
The use of an
recommended at temperatures below -25ºF (-
32ºC). If a preheat kit is not available, the TCM
will restrict full operation until the sump
temperature is increased.
10
PA1621 Maintenance Manual All Series | January 2017
Families transmission
the minimum fluid
use a fluid analysis
in the geographical
Fahrenheit
-35 -31
-25 -13
arctic preheat kit

3.3.1 Importance of Proper Fluid Level

It is important that the proper fluid level be
maintained at all times because the transmission
fluid cools, lubricates, and transmits hydraulic
power. If the fluid level is too low, the converter
and clutches do not receive an adequate supply
of fluid. If fluid level is too high, the fluid can
aerate, causing
erratically or overheat.

3.3.2 Keeping Fluid Clean

Oil must be handled in clean containers, fillers,
etc., to prevent foreign material from entering the
transmission. Place the dipstick on a clean
surface area while filling the transmission.
CAUTION
Containers or fillers that have been used to
handle antifreeze or engine coolant must
NEVER be used for handling transmission fluid.
Antifreeze
ethylene glycol that, if introduced into the
transmission, can cause the clutch plates to fail.

3.3.3 Oil Contamination

At each oil change, examine the drained oil for
evidence of dirt or water. A nominal amount of
condensation will emulsify during operation of the
transmission. However, if there is evidence of
water; check the cooler (heat exchanger) for other
signs of leakage. This, however, may also indicate
leakage from the engine oil system.

3.3.4 Metal Particles

Metal particles in the oil (except for minute
particles normally trapped in the oil filter) indicate
damage has occurred in the transmission. When
these particles are found in the sump, the
transmission must be disassembled and closely
inspected to find the source. Metal contamination
will require
transmission and cleaning of all internal and
external circuits, coolers, and all other areas
where the particles could lodge.
is
CAUTION
If excessive metal contamination has occurred,
replacement of the oil cooler and replacement
of all bearings within the transmission is
recommended.
the transmission
and coolant solutions
complete disassembly
to shift
contain
of the