ALLISON-OM1334EN

Hot Check

• Shift to

(Drive) and then to

(Reverse) to fill the hydraulic circuits with

fluid.

• Park the vehicle on a level surface and shift to

(Neutral) or

(Park). Set the

parking brake and/or emergency brakes and chock the vehicle wheels. Allow

the engine to idle (500–800 rpm).

• After wiping the dipstick clean, check the fluid level. The safe operating range

is anywhere between the FULL and ADD lines, within the HOT RUN band,

or below the HOT OVERFULL mark and above the COLD RUN band.

• If the fluid level is outside of these parameters, raise or lower the fluid level to

bring it within the correct markings on the dipstick. Approximately one quart

(one liter) of fluid is required to raise the level from the bottom to the top of

the band.

DROPBOX FLUID CHECK PROCEDURE

• Bring the dropbox to operating temperature.

• Park the vehicle on level ground, set the parking brake, and turn off the

engine.

• If a level indicator (fill tube) is used, remove the fill tube plug and check the

fluid. Full capacity is indicated when the fluid is at the top of the fill tube.

Maintain a full capacity by adding the required amount of fluid.

• If a dipstick is used, wipe the dipstick clean. Insert the dipstick into the filler

tube, remove the dipstick and check the level. The safe level is any level

between the Full and Add marks on the dipstick. If the fluid level is on or

below the Add mark, add fluid as required.

NOTE:

The fluid level rises as the temperature increases. To ensure an

accurate check, operate the transmission until the sump fluid

temperature is 160–200°F (71–93°C); converter-out temperature is

180–220°F (82–104°C). If a transmission temperature gauge is not

present, check fluid level when the engine water temperature gauge has

stabilized and the transmission has been operated under load for at least

one hour.

ALLISON AT, MT, HT SERIES ON-HIGHWAY TRANSMISSIONS

OPERATOR'S MANUAL

2000