deforming problem

STK

hello to everybody! I try to simulate problems relative to wall contact. For example the motion of a wheel due to the wall contact (road). I have considered serious problems with Fluent on these problems. The software can't get over the well known negative volumes formation, when the object comes close to a wall boundary. Does anybody has solved any such of this problem or has any idea? I have tried to use the deforming tools, but when i move an object towards a wall boundary (in the same direction not normal, imagine two edges connected in 180 degrees), the deforming boundary does not follow exactly the motion of the moving object and after few time steps i get the negative volumes message. I tried all the tools, even the user defined deforming geometry macro (DEFINE_GEOM)!! Thanks