Does this sound like a transmission problem?

[tsmtbs07]

It is a 2004 Jeep Liberty 4x4 with the 3.7L. It has an automatic transmission. I bought this Jeep from the original owner two years ago and they claimed the transmission was replaced at 90k miles. The Jeep is now at 138k miles and for a while it has been having problems where when you put it in D from P it would make a little grinding noise and take a few seconds to kick into gear. This weekend a horrible noise is coming from up under the jeep when I accelerate in the lower gears. This noise seems to disappear when I get up to 45 + mph. The fluid levels are fine. Does this sound like a transmission problem? If so does it sound like I need it completely rebuilt or could it be something smaller?

 

[yellocoyote]

Any codes?