2016 R/T Shaker 5.7 Tremec 3.91 Getrag backlash getting worse

Hello, I'll try to get to the point quick. I have the above car with 1500 easy miles on it.
the drivetrain backlash started out normal for a 3.91 with slight thud for backlash
when on off gas. Now its to the point where normal shifting causes a shudder and on/off
causes a double load (bang/bang) compared mine to another r/t same exact with 2400mi
by having both cars in 4th with no park brake and rocking the back tire fwd/bkwd by hand
Their car had what I call normal backlash maybe an inch of tire turn followed by a solid
stop each direction. BUT mine the tire turn was like twice that or more and didnt stop solid
especially fwd it sounded/felt like something in the tranny had slop and noise like gear play
plus the differential clunk when going backwards...
Final mention, when driving in 3rd or 4th the backlash actually snaps your head back/forth a bit.
This cant be right... Thanx 4 opinions in advance...

 

Whoa, that definitely sounds like something is wrong. Can you hear anything around the bellhousing area when pushing the car?

 

Sorry for my delay and thanx for your response... Absolutely right! You hear the extended knash/clicking of the gears in the tranny when rocking back and forth, sound coming specifically
from below firewall

 

I wonder if any of the pressure plate springs might have snapped.