We have seen a lot of front diff failures. These seem to happen mainly on US transfer AWD models. The US 2WD models don't seem to break them and the Euro models don't.
The way I see it is. Front wheel spin is the major cause. When the front wheels spin, the open differential allows the torque to move back and forth, from one wheel to the other, depending on which has the least grip. This sudden 'grip spin grip' places large shock loadings on the gears. Usually it is the teeth on the crown wheel or pinion that break off to become lodged between the gears, to force them apart, breaking the housing.( they reinforced the caseing on later models)
Front wheel spin should not happen. In the US transfer model when the front wheels start to spin, the TCU applies the Transfer clutch, to move the torque to the rear wheels, so that the front stops spinning. If the Transfer clutch stops working, the TCU can't move torque to the rear, to prevent the front from spinning, so the 'tyres smoke and the diff broke'.
The Euro can't lose the rear drive as it is gear driven, so the front diff won't get the same loadings. The 2WD models use torque reduction, if the front wheels accelerate quicker than the 'set rate' that is written in its look-up tables.
So the thing to watch is, if you get front wheel spin, check to see if the Transfer clutch is driving the rear wheels, if it isn't, get the clutch fixed.
Don't allow the front wheels to spin
Some like to put the FWD fuse in to smoke the tyres,
but you are diceing with 'diffstruction'
Harvey.
