4L 60 2nd Gear Harsh Upshift

Hi we have a 94 GMC Sierra, 350 engine, 4L60 Transmission, with 107,500 mile on it. Lately about 1000 miles ago, when I take off and it upshifts to 2nd gear, it seems a lot more harsh than smoother like it used to be. I have changed the transmission filter, gasket and fluid, and also flush system out. There was no visible signs of damage at all in the pan when I had it down.
The shift feels more like a Shift Kit feel, and it used to be smoother than that. Is there a home mechanic type fix for this, or am I looking at a big overhaul for the transmission?
Any suggestions that may help me out is really appreciated. Also there are no codes at all for anything.
Hopefully maybe it may just be normal for the miles that are on it.
Joe

Forgot to say that all other shifts feels good, including all downshifts. It is just when taking off, and it upshifts to 2nd, is when I fell it shift harsh or a little hard.
Joe

second accumulator should be checked for broken spring ,,,easy fix

better get it taken care of quickly. I have a GMC C1500 extended cab, that had the same thing. of course i like a harsh shift, means that there is no slippage in the transmission, but turned out that i ended up with other problems and it cost me $700 top have my trans fixed, and that was with me taking it out myself.