I've got a 96 Cherokee w/ 115k, and my mechanic who I generally trust is telling me I need both front u-joints and axles replaced.

As a guy who's generally handy with replacing alternators and water pumps and such, can yall tell me what I need to look for in these pieces when I get under the truck to make sure they really are probably going bad and that this expense is warranted?

Thanks. I really do appreciate your advice.