My auto-tranny is original and didn't need work untill 250k(ish)miles before the reverse began dying. I had the whole thing rebuilt anyway and now it has another 100k. Its important to change your tran-oil 1-2 times depending on how many miles are put on it per year. I also installed a secondary cooler(first 1 is in radiator)to keep the ATF from getting too hot in summer driving. Oh I forgt to mention, I drive hard each and every time I get into the car(40k mi.yr.)