It depends on two factors how well was it taken care of, and was it beaten on a daily basis.
If it was flushed every 30k and driven by someone who isnt likely to abuse a car, then I would say a really long time.
If it was never flushed and was driven by some teenager who though the Contour was a race car, and took off like the start of the Indy 500 from a red light most of the time then I would say not very long at all.
I know we have one member who trans has 135k ( at the time so more now) on it he said before, still the original, but he also did the drain and fill every 15k I believe it was.
