I have the TF999 in my CJ and use it as a daily driver plus it sees a fair bit of trail action. This time of year it,s mostly snow [usually 2 feet deep approx] in local sand pits and also a rocky trail when I can get out to it. The auto is pretty nice. Heat is the enemy, put an extra cooler on it and a trans temp gauge is also good. Also make sure you install the trans kickdown linkage and adjust it properly, the TF trans need that to work properly. I bought a Lokar kickdown cable from Summit Racing and it is real nice. It,s listed as a TF904/999 piece. Oddly enough, I too have a spare T176 that I,m hanging onto in case the auto dies.