Hi, I just rotated the tires on my 99 A6 with 109K. I noticed the right steering arm moves about an 1/2 inch from side to side. All the ball joints look to be ok. There are no leeks, wobbles, clunks, or anything else wrong. Is the rack going south?

 

Side to side meaning in the direction of the tierod? Could be steering tierod end wear. Some info on tierod ends here:
Audi Tie Rod - Audi Tie Rods Low Price Leader

 

Yes, tie rod side to side. after looking at the link you posted, it must be the inner tie rod end, the outer end looks good.
Thanks

 

Just did our tierod ends (TRE), along with control arms. Per the link I sent, you can see the OEM outer TRE design has a bolt head imbedded in rubber. The rubber can deteriorate over the years and it's possible this joint can get play in it. I expect it's more coomon for the outer TRE to go bad, particularly the ball joint, since it's not shielded by the track arm boot, & of course the ball joint gets exercised more. Possible you can hold the track end & see if play is localized to the TRE. Be sure to soak the TRE threads to the inner tierod with PB blaster. These are known to seize up & are a PITA to remove sometimes. On ours, ones side unscrewed easily, while the other didn't. I had to resort to using long arm pipe wrenches & jury rigging to hold inner & turn outer. Be sure to count # of turns to remove to get alignment close to before.

 

I'll do that,thanks