I am fresh fish in this pond... lets see what you can do FRF...

I have a 2001 3.0L V6 automatic.

To begin; I bought this truck from someone so I don’t know the entire history of the vehicle. The more I look under the hood the more suspicious I become about its maintenance.

Problem 1;
The Colum shifter shows the standard gears P R N D 2 1, however the low gear (1 gear) is either nonexistent or does not work. I cannot put it in the low gear, it will jut move back into the 2nd gear. I don’t know if it was never there to begin with but either way it isn’t there now. Is that normal?

Next problem:
I recently drove this truck on a road trip from California to Nebraska. The trip was about 2000 miles. I had a full bed full of boxes and furniture. As to be expected the truck struggled a little up the hills and it struggled a little up the mountains. In Vale Colorado (in the Rockies) it died a little. Pulling out of a post office I heard a loud noise and it seemed as if I lost power in the lower gears. The noise wasn’t a pop or a bang, it was more like a rock hit the undercarriage, but there were no rocks. At my next stop I noticed that the engine shook and felt like it was rumbling irregularly in reverse. It felt as if the truck’s engine was bouncing. I would drop in speed from 65 down to 35 in about a mile when going up the hills and I have no power in low gears. this wasn't the case before. The heavy vibrations occur below 2500rpm and the increase in severity as I go slower, being the worst when I am stopped in drive. If I am in park I can feel the irregular vibration but it isn’t as severe as when I am in drive and stopped. I was able to drive the rest of the trip but I felt the vibration every time the rpm’s dropped below 2500, if the engine was working and the rpm’s were above 2500 I didn’t feel it.
I need to get this fixed. I have no Check engine lights. I want to see if I can fix this myself. I don’t know how to approach this one. Is it the engine or the transmission? I suspect the transmission but I don’t know.
After taking the load out of the truck it continues to struggle. Any suggestions? Has this happened to anyone else? I’m looking for something I can work with before I take it to the repair shop and sell my soul.

Sounds like tranny to me.. Could have broken your flywheel ring gear though..

Sent from my galaxy s II, that I pay too damned much for, on the FRF App (: