tranny or transfer box failure

My X has is making a hard gear change when I accelerate and the let go of the pedal again. Also when driving downhill it does the same when changing gears- therefore I am easy on the pedal. Maybe this is of any help -When I am standing still and put it in drive there is a smal clickingsound from under the car-like it is activating the drivechain or something. My X s 2001 3.0 with 75`miles. When having a oil change the other day- I checked the axles going into the transfer box. Holding on axle still and rotating the other-there was some "give /play" inside the box.
Any clues?

[primetime]

Sounds like your tranny is starting to go bad. Can you still reverse with no problems?

no problem selecting gear and no tranny warning light.No bad sound from the gearbox either!

[X5devon]

A software update could help, take your car to the dealer or specialist with Autologic and they can put the latest software update on your gearbox, mine had a jerky change and the update cured it