I bought a '99 F-150 with 50,000 mi., 5.4, automatic transmission last week. I test drove it several times and have driven it every day (total of 200 mi) with no problems. Today, the tranny started acting a little funny. If I'm cruising along in overdrive anywhere from maybe 45mph and higher, then take my foot off the gas, the tranny drops hard into 3rd gear. The truck suddenly lurches and the engine revs from the 1800 or so rpm it was at to 2500. It doesn't do this every time I pull my foot off, only maybe 1/3 of the time. I checked the fluid, and it was full and clean (The truck was a trade-in and I think the dealer drained and refilled the tranny before I bought it). Any ideas/help would be greatly appreciated! Thanks!

 

The prior post is mine. I took the truck back to the dealer (local Ford shop) a day or two after I posted and finally got it back today, more than 2 weeks later. After trying unsuccefully for several days to find the root of the problem, they finally replaced basically the entire transmission and torque convertor. Truck runs great now, and they didn't even charge me the $100 used car warranty deductible. Plus, they gave me a rental car for free for the entire time too. I was a little frustrated to go without the truck for so long, but they took care of me so well, I can hardly complain. Unexpected, but greatly appreciated!