4wheel drive engaging but feels like it's clunkin/ slipping in the right front. on 1991 Toyota 4Runner

91 runner.. when engaged and hubs locked in the left pulls fine and the right seems to pull halfway around then slip or something. Please help...

Asked by for the 1991 Toyota 4Runner
That hub will have to be removed to inspect it, probably by a mechanic! You can put it in 4x4 with the hubs locked, jack that wheel up and test it by turning the wheel but that doesn't reveal the actual problem.