Hello all, I am having an issue with my 4wheel drive..Problem when I shift into 4high everthing works great front axle locks and we are good for about 2-3miles then the axle shifts out for 10seconds then I can here it slam back in??? I have change the 4wheel drive actuator and check vacuum at 28Hg I am sur I have no leaks just not sure of this system as to why it would lock in then out-ANY input would be greatly appreciated,,Thanks:confused: