This thing is over-the-top-reliable. I take it off-road, slam the under-belly on to rocks, bull it over large stones like a Hummer, pull over 10,000 lbs for drives well over 2 hours (it stinks of sulfer on the hills but...) - only in shop for oil/brakes.
This is my 4th 4Runner. Every version is a major improvement over the last.
A big problem with 4wd vehicles can be wheel bearing hub assemblies. 4Runner owners don't know what these things are - they never die on 4Runners... All the parts are excellent.
You're never under water with one of these - there is a whole community looking to buy used 4Runners.