I mean the VCU is a ****e idea if it causes all these problems.
One way round this is to replace the rear diff with a haldex type system, but fitting one could cause problems, Mounting points etc, something would have to be fabricated. These systems are usually wired up electronically to the ABS system, so could be quite complicated to do but not impossible. They could however be wired to a switch and could be switched on (4wd) of off (2wd).
And you could even leave your seize VCU in situ.
The other option is to replace the VCU with a limited slip diff like what you get on some front/rear wheel sports cars.
It would opperate like the VCU, but would be all mechanical, this would slip to a certain point then lock up, engaging the rear wheels, again finding a suitable part would be the challange, but Im sure it can be done.
3rd option, is repalce VCU with a proper 3rd Diff, this way no braking effect on tight turns and permi 4x4.
Simples!!! or am I talking out of my rear diff?:blabla: