there is about 3" of movement side to side maybe more in the rear drive shaft when in neutral and park brake is on wheels on the ground  

thats a bit much, tighten the pinion nut some and recheck the gear mesh.  

gear mesh is fine it looks like it in the detriot rear locker.  

there ya go...I have a eaton with a detroit locker in it that is worn pretty bad. It also has a bunch of slop.  

I called detroit and they said that its like that for better road manners but I really don't care for road manners so I wish there was some way to take all that slop out.  

I don't remember it haveing much slop for a long time, It's been abused for about 20 years.  

if I get 100,000 out of it I can't complain.  

nope.......  

how about 20,000 hard miles?  

monster_01:
there is about 3" of movement side to side maybe more in the rear drive shaft when in neutral and park brake is on wheels on the ground

You noted you had a Detroit Locker. This is how they function. They need to have that extra play to work properly. There is no way to remove the play unless you remove the locker. However, other lockers such as ARBs and OX lockers do not have the play you are referring to when locked or unlocked.

John  

Will the detroit snap something in my driveline ring gear or pinion gear axleshaft.  

Will the detroit snap the ring and pinion or a axleshaft?  

Not any worse than any other locker. The slop doesn't cause damage. The axle shafts have quite a bit of flex (twist, like a torsion bar) to them so they absorb the quick hits the slop can cause. High torque loads is what causes failure on any axle. Not the slop built into the locker.  

Cool I have the stock 4.0 with no mods at this time but I am looking into a centerforce clutch,what else would will go good with that?