So I do a lot of motorway miles in my A3, and few months ago notice in mainly 6th at around 50/55MPH I notice a whining noise if I accelerate and let go of the accelerator? My initial instinct is some sort of bearing but not sure if it’s normal? You can just about hear it in this video, it’s louder in the actual car 

 

 

Could it be the diff? I'd definitely get it booked into a garage. 

I did think this but I thought if it was diff surely it would be in all the gears? Unless it only happens at that speed? Think I'm going to have to book it in, do you think it's worth going to the dealer?

I normal garage should be able to look at it. 

Hello Ryan, 

I may be barking up wrong trees here, but I recall some non-VAG cars having accessible wearing 5th gear cogs easily accessible without major gearbox strip downs. That was sometime ago, but  maybe worth keeping in mind. 
Are you at Bridgend, S. Wales, ( rather than Scotland etc)? If so, many years ago there was a gearbox specialist known as John-the-box on the outskirts of Swansea. Maybe worth asking around the trade if he, or his successors might still be operating. 
Kind regards,

Gareth. 

52 minutes ago, Magnet said:

Hello Ryan, 

I may be barking up wrong trees here, but I recall some non-VAG cars having accessible wearing 5th gear cogs easily accessible without major gearbox strip downs. That was sometime ago, but  maybe worth keeping in mind. 
Are you at Bridgend, S. Wales, ( rather than Scotland etc)? If so, many years ago there was a gearbox specialist known as John-the-box on the outskirts of Swansea. Maybe worth asking around the trade if he, or his successors might still be operating. 
Kind regards,

Gareth. 

Hi mate, yeah I think I know what you're on about, the M32 g/box? It's very similar to that but I can't find anyone else with a VAG car or A3 with this issue. Yes, mate I'm in Bridgend, South Wales, so if I can track him down that would be ideal. I literally don't know anywhere around here that would be good to take it to. 

Cheers for the help mate, appreciate it. 

You are very welcome Ryan. Hope you have some luck in sorting. some expertise around these parts. 
Kind regards,

Gareth.