Auto HUB Locks which are already installed do the same thing, why ruin the original setup if its not broken? I mean front wheels shouldnt be locked.
@haroon_tarar try jacking the front end up and rotating the right or left tire and see if both wheels are turning, in 4X2 mode the other wheels shouldnt be turning, in 4X4 mode both wheels should be turning in opposite directions.
Enlighten me if I am wrong.