RAM CHASSIS CAB 2015 Owner's Manual page 525

Fluid Level Check
Check the fluid level when the engine is fully warmed up
and the transmission fluid is at normal operating tem-
perature. Driving with an improper fluid level will
greatly reduce the life of the transmission and of the
fluid. Check the fluid level whenever the vehicle is
serviced.
Fluid Level Check — Procedure
It is best to check the fluid level when the transmission is
at normal operating temperature (170-180°F / 77-82°C for
66RFE transmission, or 158–176°F / 70–80°C for AS66RC
transmission). This normally occurs after at least 15 miles
(25 km) of driving. At normal operating temperature the
fluid cannot be held comfortably between the fingertips.
You can read the transmission sump temperature in the
MAINTAINING YOUR VEHICLE 523
EVIC/DID display (refer to "Electronic Vehicle Informa-
tion Center (EVIC)/Driver Information Display (DID)" in
"Understanding Your Instrument Panel" for further in-
formation).
Use the following procedure to check the transmission
fluid level properly:
1. Monitor the transmission temperature using the
EVIC/DID display, and operate the vehicle as re-
quired to reach the normal operating temperature. If
the transmission is not functioning properly, or the
vehicle cannot be driven, see the NOTE and CAU-
TION below about checking the fluid level at colder
temperatures.
2. Park the vehicle on level ground.
3. Run the engine at normal idle speed for at least 60
seconds, and leave the engine running for the rest of
this procedure.
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