Windstar 95 trasmission jerk

A friend was about to have a very nice 95 windstar with 150000 miles (engine and trans replaced) towed away to a wrecker. He happily gave it to me to see if I could fix it and I have replaced the engine and all the components (timing chain, oil pump, water pump, too much to mention) and everything runs great especially after cleaning my flow sensor and replacing the front bank of the oxygen sensors.
Now my problem. The trans shifts smooth 95% of the time but I live on a hill and when pulling out and turning left up the hill the trans seems to slip a little then catch with a jerk. I am so close to having this beast ready for a friend and her kids down on their luck but I don't want to give the van just to hear that the trans is bad. I have never had to work so hard on a set of front bearings to give up now. I have read about the TRS but have no transmission codes showing up, do you think this is the problem, or is it bigger?
Thanks for your help, Wade

I have owned two 95 windstars, The first one would jerk 75% of the time when shifting into second after about a year of owning it it was totaled in a accident. Then came 95 windstar #two This did the same thing however it would jerk shifting into any gear on any teraine. after a couple of years with 98,000 mi the trany went out. I had replaced the trany filter at 50,000 and 90,000. I ended up buying a used trany for 900 at a junk yard in central IL and paying 500 for a install I then traded it in for, yea you guessed it windstar #3. This was a 2000 and I bought it with 38000 on it .I checked alot of fourms and for the most part Ford had seem to get the tranny problems solved. Well you should see the look on my face when the trany jerks when shifting gears. It does not do it near as much and seems to be more when on a incline or when I decelerate then quickly accelerate when it is tring to shift. It seems that this throws the trany off of time so to speak. I now have 83000 on it and 3 years of payment It won't make it! You probaly Know that ford had alot of recals on the 95 you may want to check into them .My front spring broke and right before a spent 200 to fix it I checked out ford and sure enough it was a recall.
I am not to sure about the tork converter in the trany I have seen in sevral forums where it went bad. I can tell you that I didnt notice any sliping in any of my windstars just the jerking. good luck!