Alright so, I have a 04 tahoe z71. I have all gears except for reverse and a loud grinding noise in reverse. It's the exact same when I switch it from 2 hi to 4hi and 4lo. Its electronic transfer case. Last time I moved it I'm pretty sure I could push it in park and it made a loud clicking noise. Pretty sure the grinding noise is coming from the transfer case. Can someone help? Thanks in advance!