Who did your Suncoast? Its on my to do list for an 04 DMax.
Sun Coast did mine

I priced out the parts and for what I wanted, it was worth buying a complete unit and the big score, warranty. I had it shipped to Connecticut, put in by a friend of mine and I dropped my old tranny (core) off at Sun Coast on my way to Sarasota. I know a buddy of mine down here that has a Sun Coast in his DMax, no complaints.

felt like it was searching for the right gear
Governor Pressure Solenoid most-likely.