Hello and welcome to the forum
For parts checking more broadly and also for a transfer box (and some other resources) check out this linked post, which is also a bit brief so search the bold terms:
https://hiace-super-custom.forumotion.com/t4468-part-numbersI can’t be certain (as I’ve never checked) but I expect the transfer box to be very widely used across many, many Toyota vehicles; also probably Hino, Nissan, Mitsubishi etc. It’s probably made by AISIN.
The point is I’d suggest using the resources in the linked post I refer to, to find the OEM part number, then take this information to a good gearbox specialist in your local area who is familiar with Toyotas of this sort of era to work out what to do.
If the case has not cracked a rebuild might be more cost effective and the linked post resources will show you how to check out all the internal parts. DIY service of the transfer box is possible but a specialist would be where I’d go to.
HTH!