CT04S4

Had a right front axle break @ 36k mi's. Audi says they have never seen it before. Drove that home a week ago and on the way home pulled into a hard right uphill drive. Heard what I thought was a new noise. A binding, light shake or shudder. I can duplicate the noise either direction, level or up a hill. If you take your car from a standstill, go full wheel lock either way and goose the gas a bit I hear it. It is not unlike the awd or 4wd cars of old that bound up the inner wheel while turning and made a noise. I just never heard it before on mine. Service took a good look at it after the drive failure. I could not duplicate it on a new S4 sitting in the lot so it seemed like a legitimate problem. After scratching their heads this week service says nothing is failed or out of alignment and they feel it is a normal situation on my car. The fact that new ones don't do it doesn't seem to indicate anything to them. I am just wondering if there are any of you out there that have this model year and/or similar miles does your car make this noise. Again, go from a stop and power dounuts are not the objective. Just go full lock on the steering, or nearly so, a hard turn and give it a little stab of the gas. Perfectly smooth or is there some tranny type noise?

s4for5_TTfor2

also, it's never a good idea to go full lock, for sure never hold it there.

I feel that when I nail the fast pedal and turn, like making a 90 degree turn at a 4 way stop.

CharlieG

I too noticed it coming from a 98.5 A4 1.8TQMS. The A4 didn't do it but the S4 does. Many others here have experienced the same thing (driveline bind) so I don't think it's anything to worry about.

Alan Smithee

I asked the same question here when I first bought the car. Some said normal, others said it's not right.

CT04S4

The new S4 we tested did not do this. Any ideas what's different?

Miah_S4Avant

It all has to do with the TorSen (Torque Sensing) diff. When you turn at a steep angle the front wheels rotate at a different rate than the rear. This itself does nothing if the car is not being engine braked or accelerating because there is no "Torque" sensed by the TorSen. But if either one is happening the diff will react to the torque by locking up so the power is sent to the wheels that appear to have more traction. The result is the same as when you lock a 4wd truck in 4hi or 4low and drive around corners....the wheels bind. I have found that how noticeable the effect is, varies with tire wear. Sometimes I have none and sometimes lots but it does change with time, not suddenly. Then when I rotate the tires, it becomes less apparent again.

But it certainly is not anything to worry about.

Hope this helps.