'04 Ranger OD light flashing, slow shift

[catsfanksu]

Our son (in college, several hours away) has an '04 Ranger we bought about 2 1/2 years ago. It has about 150,000 miles on it. He called tonight and said he went to drive away from the curb and one wheel was on ice and the other on gravel. As he accelerated to drive away, the wheel on ice slipped. Shortly after, the O/D light began flashing and would only shift from 1st to 2nd and 2nd to 3rd after revved to high rpm. He could put it in 1st and 2nd gear manually okay but light still flashing. For about a year now he has noticed a "choking" when stopped with engine running, almost like the engine might die.

I plan to call and have a transmission place look at it on Monday but am afraid to let him drive it there (or anywhere else).

I have read every forum and post I can find and there seems to be any numbers of potential reasons. I know the torque converter is a possibility but am wondering if the wheel slippage could have anything to do with the O/D light beginning to flash.

I really do not want to be taken to the cleaners from a distance so any suggestions or advice is appreciated!