oh ok Brett
hydro-static drive is a different story
I don't know much about those Ausa's, i just basing my thoughts on general knowledge of basic braking and drive systems.

Being that it is a hydro-static drive all the parts associated with the drive line are probably internal inside the cases?
If you do not see anything loose on the outside like flange bolts or even wheel lugs then it very well could be something internal that you can't see without disassembling it.