98 explorer 4x4 moves and then won’t go

[Doggone29]

I have a 98 explorer 4x4 which I am assuming has the 5r55e according to the vin sticker. Anyway, it was moving fine until I backed up one day and it would not move anymore. If you sit for a while with it in drive it will take off and go about a quarter of a mile and repeat. Does the same thing in reverse. Has good power and shifting when it moves. O/d off light is flashing. No signs of anything slipping. If you rev it up sometimes it will hit hard and go. Similar to a stall converter. Any suggestions?

 

[Mbrooks420]

Did you try it in manual second? If there’s no signs of slipping, what does it do when it doesn’t move? Fluid color? Mileage?