[Johnb]

Hi, can you damage steering rack by enabling Audi drive select on car that was not equipped.
Have a notch in steering going from 12 o clock to 11 and 1 while driving at around 50mph
Read on another side it could possibly be a result of enabling ads.

Thanks.

 

[Smokey Joe]

I very much doubt it, but I have read somewhere that one of the knuckles/ball joints on the steering stem can become dry and requires re-greasing and this can solve the issue of notchy steering.

 

[SimonRoma]

I agree with Joe, not very likely.

 

[Johnb]

Ok cheers guys, I'm guessing it's the Steering column universal joint you've mentioned. I'll give that a clean and regrease.
Just replaced all the front control arms and balljoints, tie rods etc.
Lower rear passenger control arm the big bush was completely torn, since replacing them the steering shake/shudder at highway speeds has gone.