90 S13 Rear Suspension/SubFrame hard to explain

[s13_chris]

What I have. 90 S1391 Turbo 300zx 5 Lug conversionKTS CoiloversMegan adjustable RUCAMegan adjustable tie rod

Ok, its hard to explain but the wheels/axles are floating? Not like in the air but while I'm driving. Its sparadic; it's never 'when I do this, this happens' it seems to happen when the car is going over uneven pavement. Like a v in the road or parking lot entrances. Sometimes the whole assembly will slide to the driver side and it will be out about 1/2inch or to the right and be out about 1/2inch. I just got it aligned by Les Schwab so I'm going to have them look at it again. Subframe is bolted down. Diff is bolted down.

I'm at a loss. The sliding usually only occurs when the coilovers are compressed. One more than the other. But I'm not 100% sure.. Please anyone?

[s13_chris]

It's raining outside..

Anyone have any ideas?