4x4 pulls

[95RangerAK]

my truck drives fine. in 2wd. but when i have the hubs locked it makes a shutter noise from the front right wheel. when i have the hubs locked and it in 4wd it pulls hard to the right and on bumps it makes that noise. ive check my wheel bearings and my hubs fine, u joints need replacing but that shouldnt make it pull should it? any help?

 

[95RangerAK]

nobody?

 

[ford1386]

Id replace the u joints, they dont necessarily have to get play in them to go bad they can get really tight and that could cause it to turn like crap or pull to one side when in 4 wheel drive