If I'm driving my 3.0L TF at 65-70kmph and go slightly uphill, I get something that feels like the auto transmission changing gear, but there is no change at all the engine RPM. It doesn't do it at any other time or at any other speed, just 65-70kmph and going slightly uphill?

Anyone know what this could be? Is it normal?

Do TF's have lock up torque converters?

It could just be that unlocking as the load increases..:D

If I'm driving my 3.0L TF at 65-70kmph and go slightly uphill, I get something that feels like the auto transmission changing gear, but there is no change at all the engine RPM. It doesn't do it at any other time or at any other speed, just 65-70kmph and going slightly uphill?

Anyone know what this could be? Is it normal?

Its the torque convertor locking up. Its more noticeable when underload (e.g. going up hill).
At normal cruise, you'll notice the rev dipping slightly. This is the most efficient speed for
an auto car as well. The two sides of the torque convertor are in full contact rather than
the side connected to the engine spinning up the side connected to the transmission by
the use of oil under pressure.