Ford Ranger Transmission Shift Solenoid

We Just Took My Girlfriends Ranger In To Have The Tranny Looked At. It Was Shifting Hard At Around 45mph Almost As Though The Overdrive Was...

I Am Having Issues With This And I Need To Know More About Where Are The Transmission Solenoids Are And What They Do. Picture Of One...

Just Rebuilt My A4ld Transmission I Don't Have Overdrive, My 3-4 Solenoid Is Good But My Lockup Solenoid Is Bad Could This Be Why I Don't...