Warranty

So I actually have two things going on at once. Both started at same time. I have no leaks whats so ever under my vehicle, I checked fluids they are all good. I though I got bad gas my vehicle started sputtering as I accelerated, ran fine in idol or at stop. Hesitated several times at take off like trans was slipping. Then I notice as I take off and turn there also a roaring sorta noise then it clears up and is fine after the sputtering stops. Im thinking now something wrong with steering also. I took it into GM dealership within an hour my reply is Rack and pinion is out estimated $810.00 to repair no under a warranty I'm told and also yes transmission isn't right but this is under warranty but will have to tear down and further investigate but cant be done until next Tuesday. SO after I left I was trying to find out about what was covered under warranty then I thought could these two major things be related and the noise is actually the transmission and nothing is wrong with the rack and pinion. There is no clinging an clanging no hang ups no popping noises from my steering. I don't know a lot about cars but this doesnt sound like two different things to me. Any Ideas?