Ah well, I did not know how long since the box was last split. Reason for asking was that using silicone in situations like this, it often has too much applied, pinches up "tight", but then the two halves fret and bolts come loose. There was a batch of Ferrets released, that had been in Cyprus, I have come across several of them with severe leaks form the transfer box. This is where silicone was used (not the offical recomendation) to seal the casings, and after a time it is working out, as too much was used and bolts are loose and unable to keep oil in it.