Well the two top CAs do go bad first usually. I don't know a good way to tell which one is bad. Its obvious if the boot is ripped, but if they aren't ripped, it would be tough to know just looking at them I think. If DIY and you don't mind going back in there again if after you replace a few CAs it still squeeks, then you can just replace what you think is bad.

There is a good DIY on Audiforums. I am feeling too lazy to go look it up for you, but its the one I used. Def find it before you start. You need a ball joint separator. I rented one from Autozone. Its like $60 but you get it all back once you return it. There is a little trick do doing the lower arms which is covered in the DIY. Usually the biggest headache is getting the pinch bolt out for the uppers. I used crazy amounts of PBblaster and needed some punches and a mini sledge.

FYI, a problem I had after I did mine. With all the PBblaster I used to loosen those seized bolts up, it ran down the nuckle and got in around my ABS sensors. My ABS was acting up a lot as soon as I got done. Once I popped the wheels and cleaned the sensors it completely went away. So, once you finish playing in the wheel well, pop your ABS sensors and give them a cleaning.

Like ^^^ said, get Meyle HD CAs. Thats what I used. They rule.

Anyway, good luck. Let me know if you have an questions or problems while you are working on it.

 

My A4 has been squeaking really bad lately too, but it started in the middle of winter and has been doing it for almost 2 months. I had a bad TRE and needed to put the summer tires on so I replaced the TRE, swapped tires, got an alignment, and had a state inspection done. I figured they'd figure out where the squeak was comming from when the inspection was done, but it passed without a problem. And it still squeaks. So today I crawled under the car with a pair of visegrips and wiggled each control arm. Lower front seems to be the one I am having a problem with, looks like it might be the bushing that the strut mounts to. It doesn't look too worn so I'm going to try and just grease it up and see if that takes care of the problem... a lot cheaper then buying all those control arms.

If you suspect control arm squeak try wiggeling them to determin where the noise is comming from.

 

WhenI bought mine, the control arms used to squeek like crazy, especially last winter.

So, when I replaced the worn tre's shortly after buying it, I sprayed the sh*t out of all the control arms on both sides with pb-blaster. It still squeeked some, but not as bad.

Then when I sprayed my car off at the wash in the spring, I made sure to get up in the wheel well and spray of the contol arms.

Occasionally last summer i got a little squeeking, especially if it had been dry fora week or too. So, when i had the wheels off to work on the brake pads, i sprayed the hell out of all the control arms again, all of the rubber ends. I also turned the wheels left or rightand sprayed some more.

And........
The squeeking has more or less gone away permanently, since sometime last summer I have not had any squeeking. Not all through the fall, and all through this winter.

So, get some pb blaster. and soak the hell out of them, and drive the car like a banshee, and it will probably go away.

If not, change them.

also, inspecting the control arms, none of them seemed worn or broken, and the car handles awesome, so I did not want to have to change them just because of the noise.

 

yea im going to try that pb blaster thing and if that doesnt help then im just going to try to wiggle them and see which one sqeaks and replace it during my spring break!!

 

alboz can u post a pic of the side view of ur a4 i have the same one and im thinkin about getting a 35% tint and it would be nice if i could see if its darkenough thanks, Josh

 

well i still havnet gotten them tinted. my sig. pic is sooo old its from like the 2nd day i got my car lol soo it like a year old i gotta get an updated picture cause if you couldnt tell its not a rs4 grille or clear corners in that pic. i was just about to go get tints but now my control arm is my main concern maybe when i get my tax return ill do the tints