This happened to a friend who thinks the rear disc brake trying to twist the diff off its mounts did this, bike is a couple of years old.

It was more likely caused by engine torque. A bolt could have been loose, allowing the diff to move. If it was loose, the diff would try to rotate backwards when the machine moves forward. That would put a lot of stress on the front bolt.

I ripped the front diff completely out of the frame on my Grizzly 660. I had filed the mounting holes to move the diff closer to the drive shaft. It ripped the holes right out of the frame mounting tabs.

I also broke my front diff before one year. I forgot to lock out full 4x4 and after jumped not more then 70-80 cm. i broke when i landed
I bought new one and replace it.

[2015 Z Force 800 53/Trail EPS]

Yes, very good point...and visual. Never jump..or better..land... on a front end that is locked into 4wd. The forces between the contact patch and driveline are incredible.  This is true with any manufacturer.

Yes, very good point...and visual. Never jump..or better..land... on a front end that is locked into 4wd. The forces between the contact patch and driveline are incredible.  This is true with any manufacturer.

I saw a video somewhere (maybe it was on here) of a guy who was jumping his EX and was complaining he kept braking CV Joints. It didnt take long to figure out why he was. He was landing with the 4wd on AND with his foot mashed on the pedal. It wasnt poor quality of the machine, but poor skills on the drivers part