ALLISON-OM1334EN

KEEPING FLUID CLEAN

It is absolutely necessary that the fluid put into the transmission be clean. Fluid must

be handled in clean containers, fillers, etc., to prevent foreign material from entering

the transmission. Lay dipstick in a clean place while filling the transmission.

RECOMMENDED AUTOMATIC TRANSMISSION FLUID AND

VISCOSITY GRADE — NON-MT 643R TRANSMISSIONS

Hydraulic fluids (oils) used in the transmission are important influences on

transmission performance, reliability, and durability.

• The following transmission fluid and viscosity grades are recommended.

— DEXRON

-III fluids for standard duty, on-highway applications

— Type C-4 fluids (Allison approved SAE 10W or SAE 30) for severe duty

and off-highway applications

— Type C-4 SAE 30 for all applications where the ambient temperature is

consistently above 95°F (35°C)

— Type C-4 SAE 30 for dropboxes

• Some DEXRON

-III fluids are also qualified as Type C-4 fluids. To ensure the

fluid is qualified for use in Allison transmissions, check for a DEXRON

-III or

C-4 fluid license, or approval numbers on the container, or consult the lubricant

manufacturer. Consult your Allison Transmission dealer or distributor before

using other fluid types; fluid types such as Type F, and universal farm fluids

may or may not be properly qualified for use in your Allison transmission.

• When choosing the optimum viscosity grade of fluid to use, duty cycle,

preheat capabilities, and/or geographical location must be taken into

consideration. Table 2 lists the minimum fluid temperatures at which the

CAUTION

: Do not use containers or fillers for transmission fluid

that have been used to handle any antifreeze or engine coolant solu-

tion. Antifreeze and coolant solutions contain ethylene glycol

which, if introduced into the transmission, can cause the clutch

plates to fail.

CAUTION

: Disregarding minimum fluid temperature limits can re-

sult in transmission malfunction or reduced transmission life.

ALLISON AT, MT, HT SERIES ON-HIGHWAY TRANSMISSIONS

OPERATOR'S MANUAL

2000