My suby has been making a popping noise when I turn corners or criuse without the clutch engaged. So I changed the front drivers side axel. That didnt fix it. Then one day I was stopped at a light and put it in gear but it just made this terrible loud revving noise but wouldnt move. THen I put it in $whell drive and it drove fine. Then It died and I have to jump start it everytime. Why does it only work in 4 wheel drive and what should I replace?