Hey J
The issue isnt as much of ground speed, I've locked up going down the road at 25mph approaching a sand wash / crossing, straight line on a dirt road, very little differential speed between the two rear wheels. If you hit that switch with one tire stationary and one tire turning at 10mph, you are liable to break something. Differential speed between the two axles is the killer here. Not to say under the right conditions that enough torsional stress wont break something, the M226 has Dana 60 axles down splined into a smaller carrier, there is a weak point somewhere. I advise people that do the locker mod to be at low speed or at low power settings when they lock up in order to reduce the amount of shock going across the internals when the axle locks up.
