Jeffhaynes

have a 01 silverado 5.3 4x4 with floor shift trans case. had no problems with shifting until after sitting for couple weeks then didn't want to shift out of 1st until let off gas. all other was fine up and downshift. the other day put in 4wd and not wony shift out of 1st auto or manual. hooked to tcm scanner and it's showing shifting 1-2-3 like supposed to then shifts when goes to 4th. any ideas of if I'm missing something or it a bad trans case since when put in 4wd it completely quit shifting. thanks