97 tj w/auto wont downshift to pass
 

I have a 1997 Jeep wrangler TJ, 4.0l with a 3 spd automatic. Last fall after a big 4x4 trip and lots of water it wouldn’t downshift unless you did it manually, not even when you stop at a stopsign. I checked the tranny oil, no water in it at all and correct level. I drove it shifting manual for a couple more days and the problem seemed to go away I now leave lights in 1st and it shifts through the gears…. It however doesn’t drop a gear when you matt it!! I will downshift to pass if you shift manually but not on its own. Has anyone had this problem with the 3 spd, or have any ideas on what else I can check to get this fixed?

Thanks