At 45k you need to do tranny service anyways. Get Mobil1 Synthetic 75w-90LS , it should help a little bit. The only way to cure it is get the TCU transmission software upgrade. A few tuners on this forum offer it. It should drastically improve the performance of your transmission

 

Exactly the advice I was looking for. Thank you.
Is the TCU software upgrade similar to ecu software upgrades in that some tunes are more reliable than others?
Living in the land down under, any way to get it rather than sending them the relevant component and having it posted back?

 

TCU is for the transmission computer
ECU is for the engine computer.

Only paddles shift cars have a TCU, as on manual cars the human brain does all the work.

I believe Velocity AP and RSC both have them. Ask Stu, I am sure he will be able to help you