I have a 2000 Ford F250 Powerstroke. It has an automatic in it. The tranny was replaced with a remanufactured one about a year ago. The tranny will shift just fine until you drive it for about 15 mins or so when it warms up it will upshift very hard. Any ideas?
The fluid looks good, nice and red, doesn't smell burnt. I dug up some invoices from the previous owner. One was for a transmission shop service and they wrote up harsh upshifts possible accumulator body.