4x4 question

hi new to and these nice forums, any helpful advice would be greatly appreciated...

bought a 94, 4dr 4.0lHO, 167tho has the non-vacuum disconnect front dana 30... aside from new BFG's, and a few seals, cat and o2 sensor for inspection.... the jeeps great. problem: the 4 wheel drive does not work... it needs u joints in front wheel joints, driver side has a lot of play...... i adjusted the linkage with no luck when you pull it in and drive it just kinda clunks or sorta sounds like it pops in and out over and over..... low range does work but at no point do the front wheels engage to drive.... if you lift it it goes in..... could this simply be the u joint causing enough play in the system that it does not alow it to complete the engaging????

I didn't think there was a non-vacuum disconnect front 30?!?

Did the PO change it over?

nope stock like that...... also it has the 231 case,,, 2wd 4wd PT N 4wdLR PT. it clunks and pops when you push the gas. im thinking ujoint badly enough to inhibit it all from (syncing) kinda like the tire size issue not sure tho...