Drive shafts are a good idea as the rear is exposed.
Some brake or pressure line and pressure fittings. Saw an FJ with way too much back yard hacked up lift kit.....:crazy: rip off a brake line. patch up job of the day was squeeze the line real tight with vise grips.
So therefore vise grips, bring those.

:...
Same said backyard hacked FJ exploded a rear diff. As already mentioned, a removed drive shaft was the solution for that one, winched and pulled out of the trail. FWD all the way home. You could have a spare 3rd. But the diff is busted anyway, it's not like you can save it or reuse it. Unless it's an expedition, and you must go forward, on a simple trail day it probably is not required if you can get it to a regular road.
UCA's. Seen one of these fail. Plenty stock versions are available fairly cheap, from guys replacing them with after market ones.
I broke a front axle in half. We didn't have a spare. We made a tube from an aluminium shovel, slid the 2 shaft ends into the tube and drove out of the trail..sort of. Winch and pull, but it did drive all the way home. Basically, the tube was like a broken arm cast. Just prevented the parts from flinging all over the place since one end was still attached to the wheel. So, spare front axle. The whole thing assembled. I believe left and right is the same.
Rear lower control arms get a fair amount of action. Not a bad idea to have those. And not to difficult to change if one gets bent up.
Nice thing about wheeling with the same trucks, is that you can spread the load of trail spares.