I have a 02 exp. 4wd. When I am driving above 35mph and take my foot off the gas to allow it to slow down I feel the car jumping and doing like a dong" noise. It's not hard for everyone in the car to feel it but you know your car, I don't know what that might be. I replaced the tranny b/c of a computer issue and it was doing that before and still doing it now. What can it be? Thanks.