Does that T100 have the 3.4 V6?
I've got a 1996 with the 3.4 engine and I haven't touched anything on it other than tires, batteries and fluids. Mine only has 45K miles on it and is in excellent condition. I haven't spent a dime on repairs in fifteen years but since the truck is getting long in the tooth, I'm thinking that maybe I should be carrying out some of the preventative maintenance and in particular, the timing belt. From what I've read, if one is changing the timing belt, they should also change the water pump. Problem is that the truck has been such a great vehicle, I'm a bit reluctant to bring to Toyota to have it worked on. If I do bring it in, it will be to a Toyota dealership. Might cost more but I'm confident they're probably the best people to do the work.
The external serpentine belt still looks like new hence my reluctance to mess with the timing belt. However, I'm fully aware that if the timing belt let's go, there will be serious consequences.
Have you had the timing belt changed on yours? Anyone else out there with the 3.4 V6 who hasn't changed the timing belt as per maintenance schedule (5 years/90K miles, whichever comes first)?