No, not all truck manual trans have a " granny gear " 1st gear.
Have you actually looked at the gear ratio' s. And there are four wheel drive options without low range.
As I have read " creeper gear refers to some kind of slow 4x4 driving, rock crawling, dry rough river beds"
An ultra low 1sr gear or " granny gear" was designed to take advantage of available torque very low gear for starting out with heavy gross loads and or heavy towed loads. The zero mph/ standing still to begin moving is called " breakout force " and requires more power/ force / torque to begin movement, than to continue movement once started. The redline in 63 GMC with 235 I-6 , like 11 mph in granny 1st.
This is the Newton thing " a non moving thing stays a non moving thing until you use more strength than the non moving thing.
Have you actually looked at the gear ratio' s. And there are four wheel drive options without low range.
As I have read " creeper gear refers to some kind of slow 4x4 driving, rock crawling, dry rough river beds"
An ultra low 1sr gear or " granny gear" was designed to take advantage of available torque very low gear for starting out with heavy gross loads and or heavy towed loads. The zero mph/ standing still to begin moving is called " breakout force " and requires more power/ force / torque to begin movement, than to continue movement once started. The redline in 63 GMC with 235 I-6 , like 11 mph in granny 1st.
This is the Newton thing " a non moving thing stays a non moving thing until you use more strength than the non moving thing.