2001 Chevrolet Silverado 1500 transfer case

[harvey41]

Does the transfer case turn when truck is not in 4WD?

[Purebred]

That is a yes and no.
The main shaft is turning to drive the rear wheels.
The front output shaft does not until you engage 4 wheel drive.

[Mustangman]

And stuff in the transfer case turns every time the truck moves.