Are you sure it's agod ? To me it looks like a nasty pickle.If it is indeed a nasty pickle, then make the chassis bigger.
Yes, 1.0.Setting the CSolver01's point to exactly the same as the axle attachment point in the gmf helps stability (which was what I done in Ironforge). If that's still not enough, you can try setting the motor max speed in the txt to 0.
You got my vote for RA2 Wizard. Always and forever.