mark Callaghan replied:

Rod Ive never heard of it. Are you giving it heaps or what?? how many are breaking etc etc Wheel studs are very strong and the force to required to break one off (i assume in a shearing motion) is intense. just a wild guess but have you had the tyres/wheels replaced recently?? it could be that those at the tyre service centre have used tooooo much power when replacing the nuts. if you cant undo the nuts with a normal wheel brace - they are to tight! If pneumatic spanners are used, they can over tighten the nuts id be taking it to a dealer or good service place for a check up see you in the bush

Dave replied:

the only reason you could be breaking studs is if they are not don up tight or if they have been cracked from over tightening.As the studs don't drive the wheel they just supply the means to obtain the clamping force required between the hub and the rim.I have lockers fitted front and rear in my 80 I run 36" swampers and to date all i have snaped is cv's ,crown wheels and twisted tail shafts. But i have seen studs break when not tightened correctly