Transmission shifting odd
 

I hope someone is lurking that can give guidance on an auto transmission shift issue my Xb is having. All shifts are nice and smooth at lower RPM's. However when RPM's are higher the shift from 2nd to 3rd can be very hard or at times feels like a slight shudder. By higher Rpms I mean pulling out into traffic and you have to gain some speed quickly. Not racing or abusing. The shift occurs around 40mph.

I replaced the trans filter and fluid. It seemed to shift a little smoother after this. The shift is ok on occasion when the Xb is first started and cold. The shift is also fine if I manually go through the gears with the auto shifter. I'd be happy to do more testing or supply more information if needed.

I hope this is something that can be corrected without dropping the trans. This is the last thing on my list before the Xb is ready to drive anywhere.

Also, I would like to verify that my 2006 came with the U340E. Can anyone confirm that?