rear axle movement?

got a 94 xj sport 8.25 in the rear, but with all the other xjs i haved owned or on my 79 suburban.

so what is happing is is when i need to brake hard i feel the truck move forward over the rear axle, when i let off the brake i feel the axle pop back under into possition.

now would a sye kit elimanate this problem or do i need traction bars(which i don't want)? just doesn't feel too good for my t-case.

at this time i am stock, but will be building to at least 6".

thanks for any info!

Check your spring pack pins and u-bolts!

thanks i will check that on this one, but i have had the same problemwith others. both had 4" home brewed lifts so i know those u-bolts were tight.

i will be going to a sye with a bigger lift down the road, i just wondering if that would help if i know that everything is tight and still make the movement.

thanks again!