I had a similar issue but with 4lo not working. Ended up having to replace the entire transfer case assy. I think you can only remove the entire actuator from the inside of the case. Ended up finding a low km transfer case assy for $500 and swapped it on my own.
T4R has lots of info on it.
Both engines are solid. 05+ V8's has vvti which boosts the power a bit. V6 is also an awesome engine with a supercharger option from urdusa. I run the V8 myself & I love it although its full time 4wd which hurts the mpg, expecially with big tires.
Two things I'd keep an eye on, make sure the...
I've been using a gen2 Smittybilt 9500lb on my T4R. Been running flawlessly, Paid $299 plus upgraded to synthetic line as well.
Previously ran Engo9k on my Tacoma. Good winch as well, a little slower though.
my favorite truck I've owned so far. V8 is a plus to me as well. mpg is comparable to my 4.0L 6speed tacoma (both on 35's) I just wish I had 2wd mode sometimes.