They most likely need to be taken apart, cleaned and greased!
There is a spring inside that doesnt have enough tension to engage the hub if there is to much crud, rust etc.
Just take them apart and clean all the parts and re grease them making sure everything slides freeely. look for broken parts as you go.
Get yourself a good manual like "chilton" or "haynes" if you dont already have one.
1982 cj7. Frame off. shell valley kevlar body, stainless hinges, Bestop seats and supertop, KC titanium lights, Homemade swing out tire carrier with spare front wheel bearings/hub, Built 304,DUI,Edelbrock shorty headers with dual stainless 21/2 tubes into incynerator cans 21/4 dumped out the back,Edelbrock 600cfm, performer intake and cam, Borgeson lower column, Centerforce clutch, NV-4500, Dana 300 w/custom built twin stick, Homade 1/4" steel skid plate, 2.5 soft ride w/ 1" shackle lift, 33x12.5 mtr's. Stainless fuel and brake lines, Braided hoses. more...