The PCM (engine computer) also controls the transmission. After a "reset" it controls the transmission with the default strategy and parameters. After it has enough data on the way your transmission reacts (pressures and timings) it moves away from the safer defaults and tries to optimize things. Apparently, you have some fault that keeps this from working out too well.
changing the solenoid pack only improved the shifts from park to reverse and drive the other shifts are still rough may be a bad PCM but shouldn't it be throwing a code?
i did a google search and got this info from jeep wrangler forum
"I had your same issue. You know that the hard shifiting goes away when you reset your PCM. Mark my words, it will return in a few days. I tried every trick in the book and it never went away. UNTIL, I replaced the PCM. With the remanufactured one, I have put 5000 miles on my TJ and it hasn't shifted hard ever since. Find a remanufactured PCM, get it programmed to your year, make, VIN, ETC. Very easy install. Spend the money on it now instead of having the dealer nickle and dime you to insanity. "http://www.jeepforum.com/forum/f9/hard-shift-1st-2nd-when-cold-863301/index3.html
this is exactly what happens to me hard shifting goes away transmission shifts like brand new feels like a different car then returns in a few days
is there anyway i can be sure its the PCM i don't want to buy a $500.00 part for nothing maybe i should do a PCM reflash first at the dealer