Audi 100: Gear Noise Troubleshooting (AAT)

Hi,

I own a C4 Audi with the 115-horsepower (AAT) engine and a 5-speed transmission.
Some time ago, I asked for advice from some other 'C4 enthusiasts' here.
Back then, the issue was also the noise coming from the transmission.
It was said that this transmission was probably a bit weak for the 270 Nm of torque.
Recently, I had the transmission replaced with a new one under the used car warranty.
And now, here it comes.
The noise is still there!

Does anyone have any idea what this could be?

I remember that, for example, Tommy has the same problem.

Starting from the 3rd gear, the transmission makes a rattling/whining noise, and the fluid level changes depending on the load (rolling, thrust, or traction).
The noise disappears when the clutch is disengaged.
It must be coming from the transmission, right?
Since it's an Audi/VW workshop, I can probably also rule out the possibility that they didn't actually change the transmission at all.

On Monday, I will demonstrate the car again.
Until then, any tips would be helpful!

Hello Markus,

I'm experiencing the same problem with my 2.5 TDI.
Currently, 143 horsepower.

The transmission was already making noise when I bought the car (with 160,000 km on the odometer).
Now I have 200,000 km on it, and it hasn't gotten any louder yet.

I also test drove a 2.5 TDI Kombi with a new transmission.
It was still humming, and even louder than mine.

So, it can't be a problem with the transmission itself.

As you already mentioned, the noise disappears as soon as you're rolling in 'free wheeling' mode or when you're not in gear.

After purchasing it, I added a bottle of TECFOW (ceramic coating) to the transmission oil, and it hasn't gotten worse since then.

As long as it's not too loud, it's all about driving, driving, driving!

Best regards,

Tommy D.

Hi Tommy!

Thank you for the response.
Meanwhile, I've also found a sense of calm and composure.
Since purchasing it in September, I have driven approximately 10,000 kilometers, and there have been no negative effects on the noise level.
The transmission shifts normally.
Since I mostly drive on the Autobahn, you can't really hear any rattling - it's quiet from 80 km/h onwards.
But it's just like this, when you have a car that's 'new,' you pay extra attention (although, to be fair, I should have compared the Audi to my old Golf3 - I wouldn't have noticed the transmission noise due to the engine noise, etc. )...

It's reassuring to hear that it seems to be normal (or, in VAG terminology, 'state of the art').

The 5-speed gearbox probably can't be too weak - I heard it's suitable for up to 350 Nm of torque.

Sure, here is the translation of the text from German to English:

'Supplement:'
Do you have the AAT (chipped to 143 horsepower)?
How does it drive?