Transfer case "thumping" while decelerating

[Vic_Ferrari2002]

Let me start off by telling you I have a '97 Explorer Sport 4.0 OHV Control Trac 4x4 with a 5r55e slushbox. Recently on a ride with the g/f and kids we noticed a "thumping" noise coming from under the drivers seat. It wasn't constant more like every 10 or 15 seconds while she was off the gas. so the next day i decided to crawl underneath and check the u joints. Both front and rear drive shafts had little to no movement what so ever. Next i thought maybe a a mount was broken but nothing could be found not even a loose bolt. The fluid in both the trans and transfer case are good so i don't suspect a problem there. The 4 wheel drive works fine also so i am at a loss and hoping for suggestions (or an answer from someone who had the same problem) from the forum. Any Help is appreciated!



Keith