Just in case you can't see it, I have a 1995 Chrysler Eagle Vision. Nothin special about it except for the fact that it was previously used as a taxi (450 000 KM on it

)! The transmition has been replaced 75000 KM ago but the same problem keeps reoccuring. When ever you accelerate fast, (I'm guessing) the transmition makes one loud click sound. This only happens from the range of 0 to 50 km/h or so. What could be the problem, and how could I fix it. Keep in mind that the transmition started to fail at 350 000 km. :S So replacing this one would be costly.
BTW, could I possibly replace this transmition with a standard?