I bought a 1999 f350 4x4 xlt power stroke auto trans. from a friend with 35.000 miles on it the truck was never worked until I got it. I used it to tow a 7000 lbs bobcat and trailer only about 2 days a week when my dump truck was not needed. I always used amsoil for all fluids. At 96.000 the transmission overdrive light started to flash and with in 10 miles the trans was smoked. super duty is not a term I would use for these trucks. they look super but are quite wimpy. I had it towed to a trusted trans shop and they rebuilt it for 2300.00 dollars. I know ford is aware of the problem with these units because they have remaned units in stock and was told by a parts man that they sell a lot of these replacement units. that is why I had a trans shop do the job so they could beef it up as much as possible and put extra coolers on it. After the disappointing service I got from this truck I sold it at a loss and bought a 1986 w350 dodge 4x4 and refurbished it to like new condition. no more payments no more worries about pathetic late model expensive parts to buy at highly inflated prices. and the most important part is reliability. I now dont have worry about what the next money kill shot the f350 will punish me with. this was just one of the most expensive and time consuming problems I had with this truck in the 2 1/2 years I owned it. I will add my problem with the fuel feed pump and computer in another complaint that was a 1800.00 dollar mongolianclusterf*ck in its own right. I wrote this mostly because ford was absolutely no help with my many problems with that truck and strung it along just long enough to get it out of warranty. I have had good ford trucks in the past but doubt I will ever buy a new ford truck again unless they bring back the 460 with a c6 trans now that was ford tough