Aamco is a ripoff company. Crack open the filter, if their is a lot of metal shavings inside you might need a rebuild. Also check the codes. If you just have p1811 code then just have a shop replace the pressure control soleniod. I'm going on 5000 miles after this fix and its still fine.

 

did that when i did a fluid and filter replacement n found only dirty fluid, and its weird because im not getting any codes for this. how much did that cost u to have done because ive been told about the solenoid b4

 

It was $600 all said and done. Not to expensive. You have to have a trans shop check the codes cause its manufacturer specific and most scanners won't find it.
You probably just have a bad pcs so your lucky. If something alse was failing you would see signs.

 

I have read some that the "hard shifting" may also be an item controlled by the PCM. Both my Monte and my wife's Impala has the occasional "slip into first from a dead stop". But my wife's Impala intermittently would rough shift up the gears. Before she began driving the car for the fall, I increased the line pressure a tad on the up shifts and that has stopped the rough up shifting (granted, that problem is intermittent, so it's hard to say if it's really solved), next I would like to see if I can figure out the slip into first issue.