Tires can chop on any vehicle that the tires are not rotated on. It happens to the front tires, is more prevalant and happens quicker on shorter wheel based vehicles with aggresive tread.
dk

 

Bad U-joints on yourdrive shaftwill not cause your tires to scallop. Most likely it is weak shock absorbers and/or worn ball joints and bushings on your steering/suspension.

I recently purchased my '03 with 33k miles and the original tires were well worn and scalloped causing a slightly unstable steering with bump-steerand abnormal road noise coming from the tires; sounded like *womp*womp*womp* increasing with road speed untill it became a *hummm* I replaced the tires and things improved tremendously, no more road noise and the steering stabalized for the most part, with just a little bit of bump steer still present. I noticed one day as I was driving over a neighborhood speed bump that the rear end would bounce a few times, so this was my confirmation that the shocks were weak and also explained why my tires had scalloped. All bushingsand ball joints are in good shape as confirmed by myself, an idependant LR mechanic and an LR dealer tech...so it had to be the shocks. Just replaced them with 4 new OME shocks and now thetruck is rock solid...I cannot even detect the bump-steer anymore.

I bought the shocks from West Coast British http://www.offroadexperience.com/wcb/index.html. They told me that the stock shocks on Discos are weak from day one. - Get the OME's, you won't regret it. You'll probably end up replacing your tires too. It doesn't matter how much tread depth you have, if they are badly scalloped they are gonna be noisy, shimmy and ride like sh*t. Balancing won't help much.