If you were on steep hills then I'd bet a dollar that, like these guys have said, you over heated the transmission.

 

What would be the symptoms if i overheated the transmission? The transmission fluid is a light brownish color so ill be changing it soon.

 

Symptoms would be ATF dumping out onto your exhaust, hence the white smoke. Once your ATF level drops enough you'll lose gears or will slip.

I had the same problem, thought it was oil at first until I lost 1st and 2nd. My problem turned out to be a crimped return line on my cooler was causing it to overheat. Only had issues with it at highway speeds going uphill, was on my way to the trail and it started smoking like crazy just as I was going past a couple dozen cyclists, put out a huge nasty smoke screen.

 

I need to figure out a way for my Jeep to do that on command.

 

It was funny at first... But I left about a mile long smoke screen, and burnt ATF is some nasty ****.

 

Ok... So my jeep has been dropping rpms around 2000. Like it drops all the way down to idle then goes back up. Is that my transmission? I checked my transmission oil and it was full too...