Western Star 47X 2020, Maintenance Manual

Page: 55 / 166

26–00 Safety Precautions
Safety Precautions in this section apply to all
procedures within this group.
DANGER
When working on the vehicle, shut down the en-
gine, set the parking brake, and chock the tires.
Before working under the vehicle, always place
jack stands under the frame rails to ensure the
vehicle cannot drop. Failure to follow these steps
could result in serious personal injury or death.
26–01 Detroit
™
Automated
Transmission Fluid
Change and Magnetic
Plug Cleaning
NOTICE
Transmission fluid drain intervals are based on
many factors, and are specified by the transmis-
sion manufacturer. See the details published in
the Transmission Fluid Service Information bro-
chure at
http://dtna.info/DT12FluidsManual to de-
termine oil drain intervals, and use this informa-
tion to complete the service at the specified
mileage.
Operating a transmission with the fluid level
higher or lower than recommended can result in
transmission damage. Do not overfill the transmis-
sion. Overfilling will force fluid out of the case
through the main shaft openings.
Do not mix types or brands of fluid, because of
possible incompatibility. Do not use fluid addi-
tives, friction modifiers, or extreme-pressure gear
fluids.
IMPORTANT: Drain the transmission when the
fluid is warm. If not already warm, run the en-
gine until the transmission fluid reaches operat-
ing temperature. Shift the transmission to neu-
tral (N) and shut down the engine.
1. Apply the parking brakes, and chock the rear
tires. Place a large drain pan under the transmis-
sion.
2. Clean the area around the fill plug, then remove
it from the side of the gear case. Remove the
drain plug from the bottom of the case. See
Fig.
1 .
3. Clean the fill plug and the drain plug.
4. Install a new seal on the drain plug, then install
the plug and tighten it 45 lbf·ft (60 N·m).
NOTICE
Detroit transmissions use synthetic lubricant that
meets specific requirements. To see a list of ap-
proved lubricants, transmission models, and oil
change intervals, see the Transmission Fluid Ser-
vice Information brochure at
http://dtna.info/DT12FluidsManual .
5. Add fluid until it is level with the lower edge of
the fill opening; see
Fig. 2 . See the Detroit
Transmission Fluid Service Information brochure
at
http://dtna.info/DT12FluidsManual , for identi-
fying the transmission type, estimated oil capaci-
ties, and applicable oil specifications.
NOTE: In all cases, the correct fluid level is es-
tablished by checking at the fill opening.
6. Operate the engine for five minutes after filling
the transmission, then check the fluid level again.
7. Install a new seal on the fill plug, then install the
plug and tighten it 45 lbf·ft (60 N·m).
8. Operate the vehicle to check for correct opera-
tion.
f261531 12/19/2019
1
2
1. Fill Plug 2. Drain Plug
Fig. 1, Drain and Fill Plugs, Detroit Automated
Transmissions
Transmission
26
47X and 49X Maintenance Manual, June 2021
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