My buddy has a 97 or 98 Tahoe with push button 4x4. He says recently when he tries to engage 4x4 it makes a grinding noise. I figured a bad actuator but I really am not certain. I haven't ridden in it since this started, or heard it first hand. Any thoughts? Also his axle seals at both ends of his front differential are leaking. How big of a pain are these? Hes wondering if it would be about the same cost with all the work to just swap it to straight axle. I can't convince him to lose the stupid body lift he has though.