4wd problem

Forum: 

hello,having big problem engaging 4wd,ithink transfer box could be problem,done usual checked front manual hubs seem ok,as soon as i go off road front wheels dont move back wheels spin,any clues before i start to search for transfer box

problem

more likely to be the vacuum pump or vacuum switches for engaging 4wd had a similar problem, changed the vac switch on transfer box no problem.
keith