slipping transmission

[jbjdoc]

New to the forum... I have a 2001 Rangie 4.6. The transmission seems to be slipping under load, various gears, including reverse, all under load, during hard acceleration (although it seems to be taking less load to cause the popping and slipping). No codes showing. any suggestions????

[jbjdoc]

Another thought, could this actually be a transfer case chain slipping? Any thoughts?