I'm not sure whats going on here but my transfer case when shifted into 4h sounds like it is going to blow. When I step on the go peddle it goes away, let off and it sounds like it's grinding. 4l seems to work fine. It seems like it's not fully engaging, this is whether I'm moving or not, clutch in or not, or on the peddle or not . I've tried everything, crawled under and check all the u-joints and everthing appears good. What do you think?