how much mud did the taco see? -seal and radiator issues
what size of tires and wheels are you running? -tie rod and power steering issues

my 99 taco had over 90k miles on it when i got rid of it back in 2002. i ran it hard for most of those miles on 35" with amsoil oil/fluids change religiously. yet i still had problems with alot of my seals (engine, trans, t/c, & axles) and tie rods. trucks in general don't like mud especially when you don't wash it off until weeks later. and the rack & pinion is crap especially when you run oversize tires & wheels.

of course, i have no idea if your taco is stock or not.