Do the Z8 have the rear disc on the tailshaft as the X8 does ? My mate has an X8 that's a couple of years old and this happened to him, he thinks it's from the force of the brake when applied is trying to twist the diff in it's mounts?

[2015 Z Force 800 53/Trail EPS]

The Z8s have just a parking brake there and have 4-wheel disk brakes. But...that doesn't mean that with some loose mount bolts the torque from the driveline won't do something like that to them too. Something else to check...