I've got 93,000 miles on my truck.

While pulling away from a toll booth on my commute, I've consistently noticed that the RPMs drop from about 2900 to 2500 in 3rd while giving it steady gas. Almost like a gear change, but it is still in third. It doesn't do this in manual mode and it only does it in third gear.

From what I've researched, it is likely the torque converter. Apparently it operates in a partial-slip mode from about 25-56mph.

Has anyone else noticed this, aka is it normal?

 

Torque converter lockup, my Discovery II does the exact same.

Heck, if I pin it in sport mode, it'll lock up in whatever gear it downshifts to, or if I pin it from a stop it'll lock up in 1st gear.

 

Yeah it's just something the ZF6HP does to smooth shifting on their luxury models, and presumably it expands the lift of driveline parts dramatically. Personally I think it's annoying, I'm always expecting a solid shift and it doesn't really ever do what I'm waiting for it to do lol. Partial throttle is the worst.

I think the shift program is a little more aggressive in the range rover sport, from what I recall.

The transmission is capable of variable lockup in all forward gears from what I remember.

 

Depending on mileage and time since the pan was changed you could try servicing the Tranny and then asking GAP for the custom transmission firmware that tries to address this. I have heard a few people say they did it, only downside was apparently it is less good at detecting when to downshift in auto mode.