Locker in front axle

I am wanting to put a locker in my wife's 96 XJ daily driver but she doesn't want the negative effects of tires chirping, and all that crap. A buddy mentioned that I should just put a locker in the front and leave the rear open. That makes sense because the front is only powered when in 4wd. My question is how will the non dico front axle deal with a locker since it technically does turn all the time till you engage the xfer case? Will the locker only engage when in 4wd and power is applied? Can someone clear this up?

BTW there aren't funds for a selectable locker and I am looking for something used or cheap!

Thanks

I have a lock right in my 96 and it only engages when you pull the lever.

if installed properly, it will only engage when there is more torque applied to the locker from the carrier than from the shafts. in other words, if installed properly, it will only lock up when in 4wd and when you are on the gas. 2wd and coasting turns in 4wd should leave it unlocked, though you might here a faint clicking.