From our 2018 Desert trip. All I was trying to do was position my truck in the sand near Lake Powell and snapped the driver-side u-joint. All I had to do was put it in reverse and tip into the throttle. SNAP!
Passenger side stub snapped in a sandy wash coming down on the Eva Conover trail in Central Utah.
Here's the passenger side stub and long side shaft after making a pretty long way down the Flat Iron Mesa Trail south of Moab.
Before all the naysayers start screaming to get a D60, hold your horses a bit. There is a common thread through all the failures. Yes it all happened in Utah on three different trips but that's not it. Each time one broke I was backing up with lite to moderate throttle input. Between the automatic trans I had at the time and the tru-trac limited slip diff, myself and a few of my buddies have theorized it's the auto trans holding torque on the drivelines when the shift from drive to reverse happens. Add the tru-trac into the mix and the change in direction causes a quick release of torque that hammers the tire with the most traction. The result is the same. Snap.
I did one more trip to Utah with the old combo (5.3/auto). The terrain was similar, including the same trail I broke the passenger side outer on. I changed one thing in my process. If I got stuck I made sure to shift the trans to neutral and pause before going the other way. I did get hung up a couple of times and managed to do this without snapping a shaft.
I've had two solid trips with the 8.1/nv4500 combo and the first one was some solid rockcrawling in Moab. No break.
I'll get some Chrome-moly shafts to stuff in the D44 before getting a D60.