07 LTZ Z71 Rattle Noise At 65-73mph

[BCJ954]

My 07 Z71 has a rattle noise that sounds like it is coming from the front. I have searched high and low to find anyone else with this problem and all I could find was everyone saying at low speed, steering shaft or it rattles with any bump. The noise I am hearing sounds like a washer spinning on a shaft. It only does it around 65-73 MPH. The only thing I have done to it is replaced the passenger side cv axle about a year ago when it broke. This was before the noise started. I replaced it on the drivers side about three weeks ago due to the noise and it popping in 4wheel. It fixed the popping of course but not the rattle noise. I checked everything I could think to check but have had no luck. The one thing I am leaning towards more than anything is I grabbed the axle where it is bolted to the flange that goes into the differential and tried to turn forward and reverse to check for play I noticed it move up and down a little where it goes in the differential just a bit. It wasn't much but was noticeable. I am just curious as to where I need to start looking, what to look at and has anybody had this issue. I'm at a loss right now.

[gmtech4]

its not the shaft ,,,,,,get a flashlight and start looking close ,shocks,sway bar links /frt diff mount bolt washers on right side if it has them ,,,,grab touch everything ,,,,,or take it in ,,,,DO NOT start throwing parts at it

[BCJ954]

I will look at it again and inspect it all thoroughly. If I still can't find it then I guess it is off to the dealership to let them find it, tell me so I can fix it. Hope it isn't anything major.