I have a similar problem. It has a hard shift from 1st to 2nd. I tried to adjust the cable, but the 1/2 round button wouldn't stay pushed down and I didn't hear any clicks when opening up the throttle linkage as suggested in another post.
The throttle boby cable connects the throttle to the tranny via cable. This controls how your tranny shifts. When you push the gas to the floor it causes the tranny to shift harder at higher rpm's, and just the opposite when you are light on the gas.
To adjust find the end that hooks to the throttle body. You'll notice that where the cable clips into the metal mounting bracket, there is a plastic housing that has a button that is in the shape of a half circle. Press it and push the cable into the plastic section, it should move in about 1/4" to 1/2". Now you have reset the cable and are ready to adjust it. To set the cable simply get in the drivers seat and press the gas pedal all the way to the floor (with the engine off). While you do this you should hear a series of clicks from the throttle body area, that is the cable setting itself. Thats it, give it a try. Hope this makes sense to you, it is very easy to do.
I think that is probably the problem, because there was some adjustment made, and it did change the hard shift a little bit, but I am not sure if I am doing it right, or if the adjuster 1/2 circle thing is screwed up since it won't stay pushed in and there are no clicks. Any suggestions? Is there an adjustment at the other end of the cable?