Ok took my JKU to shop on Wed .... They checked everything out underneath..., in stalled new 35" MT mtz's and it's all ok.
I think as someone mentioned earlier...

In my situation it could have been one tire lower in air combined with a slight uneven driveway.... Though by eye it looked fine. I took tape measure myself after new tires installed and it's bang on. Sorry I couldn't be any help... I'm damn happy my rig is ok though. Rob