What year is that truck? It reminds me of my first truck, and I swear, I bet it is STILL on the road! I drove it through water over the hood, until a landscape timber rolled up to the windshield, and it NEVER quit running! I pulled it up to high ground and went back the next day expecting to have to tow it, and the damned thing started! So I had it serviced and it never missed a beat. It also never knew it was a 2wd because I drove it off road all the time!
Toyota trucks have always been tough little die hards, and that is why I am driving my third one.