Hi Stan,
Don't know if you fixed your problem, so I'll add this bit just in case...
My TXII which is nearly 4 now had a problem for some time after I bought it which sounds a little similar to yours. I found the box holding the gears far too long and making the engine race more than I was comfortable with.
Eventually I found the problem to be that the kick down cable was overly adjusted! This makes the gearbox think you have the throttle down more than you do - i.e. are accelerating hard, when you're not!
This was how it came from the factory!!!!!!!! I undid the nut on the cable under the bonnet, allowing the cable to fully relax. Now I have much smoother changes - though it's well known that this gearbox, although reliable, is hardly smooth!
