mmm am i missing the point but it has nothing to do with surpension but more to do with 2 + ton and gravity and going to the place of least resistance :)
Belive me rangie's disco's, 90's all do it and more agressive tyres make it less liley to do it but belive me even a 90 with a set of simex 36's extreme treckers will still slip into ruts on a muddy track and at times there is not alot you can do about it :)

