[4.6 RR]

I just completed rebuilding 2002 4.6 RR. I have one problem to which I cannot seem to find the solution. Onboard computer keeps displaying the GEARBOX OVERHEAT message. Transmission shifts fine in both modes, there is no leaks or any disconnected wires…
Did anybody have come across this before, would this mean that this is a time to visit Land Rover dealer.
Any thoughts, help, ideas would be appreciated.