My current car:
'87 S4 T2
dyno'ed at 177 at the wheel
also have KYB 8 way adjustable and poly bushings


So my problem:

Look at the picture, see the crack, my differential/driveshaft (at the connection of the two) would bounce up and then down, causing a bang sound. After inspection I noticed the crack between the two nuts that hold the subframe hindge to the differential. My question is what could have caused this? Body flex? Too much power? (177 isnt much). If its any of those issue's i'm sure someone else would have had an issue with this.

The most logical explanation is the bushing that is on top of the subframe keeping the differential/driveshaft from bouncing, broke. If so, how would i remove this?

 

the proper name is called the diff mount. They break with wheel hop.