Transmission BANG
 

my 2003 3.3 has a very annoying trans issue.
When accelerating hard it changes gear nice and smooth at 5500rpm.
When gently cruising around it changes fine at about 2/2500 rpm
But if your on the motorway and accelerating normaly and you lift off the power to bring on a gear change there is an enormous bang as it takes the next gear its one bang and its loud like the engine hitting the bulk head.??
oil level is fine clean and not burnt.

maybe a bad engine or tranny mount?