Need help im in trouble! can't figure how to fix my jeeps death wobble?

I have a 1996 4door jeep cherokee (regular).....i got brand new tires (stock size on 15 inch rims also stock) a few months ago all ballanced and everthing....one has a small valve leak (front driver) and i have to fill it ocasionally. i have had the death wobbel a few times before i put my tires on. now i put a 3" lift on and it does it every time on the highway everything looks normal execpt for MY AXEL MOVES SIDE TO SIDE when im turn my tires track bar looks fine everything looks great? i really want to keep my lift put if it will fix the problem then i will take it off. ive heard that i should and should not convert to leaf springs in the front... whats your take? thank you so much for reading all of this!!!!!!1