Why are the drive shafts on most of the 4x4 trucks so weak? I've lost count of how many times the front or rear drive shaft has broken while playing, even doing light off-road tracks and going at low to moderate speeds. A few times, the drive shaft has broken while running on flat ground with zero damage to the vehicle.
Were the driveshafts scraping the ground ? Is the motor correctly attached ? I've almost never broken the driveshafts of a 4x4, maybe clear your cache and try in safe mode ?
4x4s have really strong driveshafts, both irl and in game, maybe you removed the skidplate from the Hopper or something, because it shouldn't just break like that. I can only break one during intense police chases that last several minutes and damage the cars a lot. Or during big jumps like on the DTD Proving Ground map.
are you using custom engine mods without engine mounts? those cause the driveshaft to flap around and break