I'm new here. Hope I'm in the right place.

I have a 2004 Chevy S10 (V6)with an automatic transmison. Yesterday I made a hurry up move into traffic that scared me. The engine reved to about 2500 rpm but the truck barely moved.
I checked the fluid when I got home and added a little but it didn't seem to fix the problem. It seems to have a hard time shifting under just a normal load of going up a hill. I'm hoping that maybe someone has seen this problem and it'* an easy fix!

Thanks,

Doug

When your driving will it accel fine then just quit going and rev? aka slip?

No. I haven't noticed that yet. Seems to be just when I accel or when it tries to shift going up hill.

Are there any obvious things that I should look for to start with?