The vehicle is auto 4wd and I have looked at several different forums with no luck to a possible answer. It does look like it may be a common problem with these years of explorers. No check engine light.
My car has 160000 miles.
My car has an automatic transmission.
Hello. I think what we are looking for here are possible problems caused by a "torque-reversal" in the drivetrain. That is, when accelerating or maintaining road speed, the engine/transmission and all the drive links (driveshafts, differentials, transfer case, etc.) have force applied in one direction. When you let off the accelerator, the vehicle is now forcing all these bits to turn the engine - in the opposite direction. So any loose play in U-joints, CV joints, bearings, motor or transmission mounts, etc. catches this force. The loose motion, or "slop," can cause clanging, "thunk," or shifting of the engine/transmission on loose mounts. I would recommend having a your noise inspected by a professional mechanic, such as one from YourMechanic, to diagnose this problem, get an accurate assessment of damage and cost estimate for repairs.