Gnarly4x: Reread my whole statement. Unlocked tires change speed in curves. But when locked the inside tire must slip when going around a curve or you will go straight. Locked diffs don't effect steering at 0 mph and very minimum at crawler speeds.
Mudmaster: You're correct. I know this. I have a Detroit in the rear. I'm not talking about going down the road at 45mph with the hubs locked and trying to turn. I'm talking about sitting on level ground on gravel and trying to turn.
I still have lockouts so the front is never truly locked in unless the hubs are. Truck drives great in 2wd down the road with the hubs unlocked. No turning issues at all. The issue arises when the truck stopped and the hubs are locked in. Once this is done it immediately will not turn left past straight. Without moving an inch. But it will turn right.