Centre differential - duplicate from European forum

1992 JDM model. I am getting a problem when the steering is on full lock. It's almost as if I had put the fuse in to lock the centre differential. But there is no fuse, so I think the centre differential is locking up. There are no symptoms at all when driving normally. Any other potential suggestions?
If that is the case, then is this a separate physical unit from the gearbox? Can I replace it without having to change the gearbox as well, as the gearbox appears to be OK.
If yes, has anyone got a spare?

Are you sure this isnt a steering issue?

Yes, it sounds more like your CV Joints are shot? I would take a quick look at the CV Joint boots to see if there is a rip in one of them?

An interesting thought. I have just replaced one of the driveshafts which cured one problem, and I am about to replace the other. Perhaps I will hold off on any gearbox work until the other driveshaft has been replaced. I plan to run some tests with the diff lock fuse in place over the weekend which may help me to isolate the problem as well. I will let you know the outcome.