Forum:
How expensive is this going to be ... 
1994 Daihatsu 4trak - initial diagnosis appears to be the the rear 'diff' is 'knackered' (Lots of loud clunking noises, followed by the appearance of smoke from the black box thingy on the back axel). RAC man asked 'Are you going to get it fixed?'.
Do I need a new car?
REAR DIFF
Sounds a bit like the end of that diff but look on ebay for one being broken and replace the lot. Bear in mind that they are heavy so to collect you will need a few strong hands and a preferably an old Pickup or the like.
OLDMINIMAN
M J Young
Options
Another option is to buy a scrap vehicle for spares, particularly if it is rotten, break this, use the spares you need, keep the ones you want, and sell off the rest.
Many people who i know do this usually make a profit as well as getting a stock of spares for future use.