Gents!
So I have noticed that when accelerating to motorway speeds, as I pass about 45/50, There is a whining sound, almost like a whirring/medium pitch humming sound that increases in pitch as speed goes up.

2014 A5 2.0TDI (134)
114k miles
0B1 6-speed manual gearbox (0B1 is the code Audi gave me so I could look into getting repairs)
 

I originally though it could be worn gear sets as the car had spent pretty much all of its life before I bought it as a motorway cruiser between B'ham and Bristol - However, I've noticed that as time/mileage has passed, the noise is appearing at lower speeds. Originally the sound was only made in 5th & 6th gears, but now I've added about 1k miles on it since noise started, I can hit high revs in 4th and hear the sound starting.
I have been told by a gearbox centre that the only time he has seen a gearbox of the type I have, it was the journal bearing at the end of the casing that couldn't be replaced due to Audi not selling the part needed and it being proprietary, meaning I'd need a new gearbox. Given the potential costs involved of what I've been told, I figured I would ask around on here to see if you guys have any insights, thoughts, or had a similar or identical problem in the past.

I was considering taking it in for a gearbox oil change and asking them to just add in a little extra as a few cars I've owned in the past did benefit from such a move - not to hide a problem.

Any advice or thoughts would be appreciated. I'll look into getting a video recording and hopefully it'll pick up the sound in the coming days, see if you guys know the noise.

Cheers Guys!

I had the start of similar in my A4 B8 diesel manual gearbox at around 140k miles.

The garage I take my cars to poured a bottle of Slick 50 in there and the noise went away, and didn't return.

I sold it at 243k miles and still no issues.

Worth a try.

21 hours ago, Lynx said:

Gents!
So I have noticed that when accelerating to motorway speeds, as I pass about 45/50, There is a whining sound, almost like a whirring/medium pitch humming sound that increases in pitch as speed goes up.

2014 A5 2.0TDI (134)
114k miles
0B1 6-speed manual gearbox (0B1 is the code Audi gave me so I could look into getting repairs)
 

I originally though it could be worn gear sets as the car had spent pretty much all of its life before I bought it as a motorway cruiser between B'ham and Bristol - However, I've noticed that as time/mileage has passed, the noise is appearing at lower speeds. Originally the sound was only made in 5th & 6th gears, but now I've added about 1k miles on it since noise started, I can hit high revs in 4th and hear the sound starting.
I have been told by a gearbox centre that the only time he has seen a gearbox of the type I have, it was the journal bearing at the end of the casing that couldn't be replaced due to Audi not selling the part needed and it being proprietary, meaning I'd need a new gearbox. Given the potential costs involved of what I've been told, I figured I would ask around on here to see if you guys have any insights, thoughts, or had a similar or identical problem in the past.

I was considering taking it in for a gearbox oil change and asking them to just add in a little extra as a few cars I've owned in the past did benefit from such a move - not to hide a problem.

Any advice or thoughts would be appreciated. I'll look into getting a video recording and hopefully it'll pick up the sound in the coming days, see if you guys know the noise.

Cheers Guys!

Hi have you had the oil level checked, chances are that if its been beasted up and down the motorway the oil is knackered although it sounds like a diminishing oil level to me ,get the oil changed and add the Slick 50 its the cheapest option.

Steve.

On 6/16/2022 at 11:00 PM, Lynx said:

Gents!
So I have noticed that when accelerating to motorway speeds, as I pass about 45/50, There is a whining sound, almost like a whirring/medium pitch humming sound that increases in pitch as speed goes up.

2014 A5 2.0TDI (134)
114k miles
0B1 6-speed manual gearbox (0B1 is the code Audi gave me so I could look into getting repairs)
 

I originally though it could be worn gear sets as the car had spent pretty much all of its life before I bought it as a motorway cruiser between B'ham and Bristol - However, I've noticed that as time/mileage has passed, the noise is appearing at lower speeds. Originally the sound was only made in 5th & 6th gears, but now I've added about 1k miles on it since noise started, I can hit high revs in 4th and hear the sound starting.
I have been told by a gearbox centre that the only time he has seen a gearbox of the type I have, it was the journal bearing at the end of the casing that couldn't be replaced due to Audi not selling the part needed and it being proprietary, meaning I'd need a new gearbox. Given the potential costs involved of what I've been told, I figured I would ask around on here to see if you guys have any insights, thoughts, or had a similar or identical problem in the past.

I was considering taking it in for a gearbox oil change and asking them to just add in a little extra as a few cars I've owned in the past did benefit from such a move - not to hide a problem.

Any advice or thoughts would be appreciated. I'll look into getting a video recording and hopefully it'll pick up the sound in the coming days, see if you guys know the noise.

Cheers Guys!

Have you resolved this?

On 6/17/2022 at 5:09 PM, jdragon said:

I had the start of similar in my A4 B8 diesel manual gearbox at around 140k miles.

The garage I take my cars to poured a bottle of Slick 50 in there and the noise went away, and didn't return.

I sold it at 243k miles and still no issues.

Worth a try.

Is there any chance you remember which slick 50 your mechanic used. Since, I  only found Slick 50 engine treatment.