If you have a push button on the dash just be rolling very slowly and push 4hi and it should go in smoothly, If you try to do it stopped it may bang when you start to move. when you go to disengage it you may need to stop and back up. If it is a manual locking system you will need to get out and turn the front hubs to lock it in and shift to 4hi but i don't think yours is manual locking unless someone changed the factory setup