Allison Transmission 3000 Mechanic's Tips page 26

4. With the engine running, remove the dipstick from the tube and wipe the
dipstick clean.
5. Insert the dipstick into the tube until it stops and then remove. Read the
fluid level. Repeat the test procedure to verify the reading.
6. If the fluid level is between the "COLD ADD" and the "COLD FULL"
bands (refer to Figure 2–2), the transmission may be operated until the fluid
is hot enough to perform a "HOT RUN" test. If the fluid level is not
between the "COLD ADD" and the "COLD FULL" bands, add or drain
fluid as necessary to bring it to the middle of this level.
7. Perform a hot test at the first opportunity after the normal operating sump
temperature of 71°C–93°C (160°F–200°F) is reached.
d. Hot Test Procedure.
CAUTION: The fluid level rises as temperature increases. The fluid
must be hot to be sure of an accurate test.
1. Operate the transmission in D (Drive) until normal operating temperatures
are reached:
— Sump temperature 71°C–93°C (160°F–200°F)
— Converter-out temperature 82°C–104°C (180°F–220°F)
2. Park the vehicle on a level surface and shift to N (Neutral). Apply the
parking brake and chock the wheels. Allow the engine to idle
(500–800 rpm).
3. With the engine running, remove the dipstick from the tube and wipe clean.
4. Insert the dipstick into the tube until it stops. Then remove it. Read fluid
level.
5. Repeat the test procedure to verify the reading.
NOTE: Safe operating level is within the "HOT RUN" band on the
dipstick. The "HOT RUN" band is between the "HOT FULL" and the
"HOT ADD" bands. Refer to Figure 2–2.
• If the fluid level is not between the HOT FULL and HOT ADD bands
(refer to Figure 2–2), add or drain fluid as necessary to bring the fluid level
within these bands.
e. Consistency of Readings. Always determine the fluid level at least twice,
with the engine running. Consistency (repeatable readings) is important to
maintaining accuracy of the readings. If inconsistent readings persist, inspect the
transmission breather to be sure it is clean and unclogged.
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