When do you check the tranny fluid? Warm or cold?

[Cobra2401]

Was wondering if it made a difference on checking the tranny fluid? I have the m923 with the automatic Allison transmission. Do you check it warm or cold? I know it needs to be running and in neutral. Thanks for any help.

 

[cajun666]

Cold just to make sure you have some in it.
But to tell what you got in there and it at correct lever warm.

 

[wheelspinner]

Yes, to both questions. You are supposed to check the physical level first (cold check), just to make sure there is some, then drive it enough (hot check) to reach operating temp, then check it again. The manual has a very specific process, its two pages long, too long for a complete answer here.