I carry the tools I need to make the repairs for the parts that I carry. So If I carry spare ball joints, I carry the correct wrenches and sockets to replace them. If you carry a spare belt, then I carry the tools to change it. If you carry an axle carry the tools to change it. No use carrying a bunch of tools, especially heavy wrenches and sockets if you don't carry spare parts.
I also carry spare bolts for the suspension components and wrenches to match.
The best way to know what to carry is to buy that spare belt, get in your shop or garage and go through the steps to change it. Make a list of tools you used. Then do the same for axles, ball joints, etc.
Then on top of these wrenches and sockets, add a few screwdrivers, dykes, needle nose, Channellocks, Vice grips, etc
I carry four Packouts full of tools, spare parts and supplies. Two in the bed and two behind the passenger seats. We ride alone most of the time and I don't depend on others to help me or have parts to fix my stuff