Audi A4 8K Driveshaft Joint

Hi,
When driving with the steering wheel turned sharply (e.g., in a parking garage), my Audi makes rumbling noises that seem to be coming from the front axle or the front wheels.
I've experienced something similar in my old Passat before, and in that case, it turned out to be a problem with the ball joints.
When I switched to my winter tires, I inspected all the joints. The lower outer axle joints give way when levered with the tire iron, so they don't just pivot like a ball joint (see pictures).
With the winter tires, the noise is almost gone.
I had the car on the stage at the . However, he said that it was the rubber-mounted joints that were likely to give way.
I can't quite picture that; to me, the joint looks like a typical ball joint. The other support arms attached to the wheel bearing housing are also mounted in a similar way.
Does anyone know about these joints?
hg
Herbert.

Hello Herbert!

I don't know the exact construction of the Audi control arms, but based on my experience, some BMWs have joints that are decoupled from the control arm by a rubber layer. I hope you can now understand what I mean. This would explain the "give" you're experiencing.

Here's how I would test the joints: Place the car on the ground and vigorously shake the wheel that is not turned. Then, a second person can feel the joints. This way, you can identify which joints are in a position where the most wear is likely to occur. If you lift the car onto a lift, everything will be suspended, and the joints may be in a position where there is currently no wear.

Best regards,
Johannes.

It might be worth checking with TÜV or Dekra to see if they can perform a check using a vibrating plate.

It is also possible that the existing play disappears when the joint is in a different position.

Hi,

Quote:

I don't know the exact structure of the Audi control arms, but based on my experience, I can tell you that in some BMWs, the joints connecting to the control arm are decoupled by a rubber layer.

I hope you can now understand what I mean. This would explain the give.
That was also the explanation at the }. The service technician found the behavior to be normal. The car was on the lift with its wheels raised.
Of course, testing with wheels on a shaker table is one option.
hg
Herbert.

Hi!
Okay, what you're describing sounds pretty clearly like the joints of the driveshaft to me.
Depending on the speed and load, it can be perceived as a rapid rattling, cracking, or popping sound.


Was there something there before?
Are the cuffs broken? Has water and dirt gotten inside?
After many years and many kilometers, the grease can simply be used up or dried out.
Or, in some cases, the joints have worn out.

If it were my own car, I would first, in a systematic way, loosen the tension bands on the cuffs and inject some oil into them with a syringe. Don't forget the inner joints either. Always do one at a time, and then test.

Here's how you might be able to narrow down the problem.

Hi,
The joints of the drive shafts have been clearly ruled out.
It concerns a noise that may be related to tire pressure and occurs when making tight turns.
hg
Herbert.