2001 XLT V6/4.0 hesitation issues

[af66]

First time poster here...hoping somebody can give me a point of reference to start with diagnosing this problem I'm having with my 2001 XLT V6/4.0. I'm experiencing a hesitation (or sudden jerk) when I'm driving at a constant speed. It has been happening sporadically for a few weeks now...only in the last few days is it happening more than once a day. basically, the car starts up fine, idles normally, acceleration isn't a problem...it's just when it's driving at a steady speed with light pressure applied to the accelerator. It seems to be primarily at or around 40mph or in some instances at 55mph. Like I said, no problems accelerating, decelerating or sitting at idle and no problems starting up the car. Before I started to replace things that might not be related or be causing the problem, I figured I'd ask you guys and see if someone has had (or is aware of) similar symptoms that would point me in the direction of how to go about fixing it. I should also mention that it hasn't triggered the check engine light yet.
Thanks in advance, and any help would be greatly appreciated.