I really don't travel much on the highway but today I had to. I have no issues with the tranny shifting hard or anything it just seems to get louder the at about 100km/h and the rpm just gets higher.

When does overdrive kick in? At about 100km/h the rpm is at 2100 and the faster I go the higher the rpm gets, is this normal, is there only 4 gears in this tranny? Searched for info but most info is for the discovery.