NODB8

Anyone ever see this happen before? Apologies in advance, newbie here and more enthusiast than skilled mechanic. I don't know if this is related, but a few months back I had both outer tie rod ends replaced on my 2000 A8 4.2 Quattro - local mechanic. I understand the outer tie rod ends are on the upper part of the suspension yes? This photo is from the lower driverside - reaching in behind the front wheel with my iPhone to snap this shot.



Happened yesterday, pulling out of my parking space in my apartment complex, left turn out of my space, and 20 feet later, going over the speed bump I hear a POP under the left front. It felt like I just got a flat tire. When I get out and look, the wheel is nearly rubbing the top of the wheel well! Still inflated. Holy moley! So I grab my iPhone and reach behind the wheel an snap some pictures. How the heck does this lower arm pop out - doesn't even look like the threads suffered any damage? I'm not sure how all of this is supposed to connect together, but am I wrong to assume the mechanic did not put the suspension back together properly? The scary thing is I've been driving with this for a couple of months. Two very minor symptoms that looking back might have been precursors. 1) vibration in the right front wheel under braking - I assumed it was a the rotor that needed replacing... perhaps it still does? 2) subtle popping sound under the driver footwell in the last week - usually when going over the speed bumps in my parking garage. Glad this happened in my parking garage and not out on the roadway at speed... :-{
Can anyone give some insight in to what exactly is missing from this picture? How the heck are the threads clean on the top of that bolt? What broke and where? Am I right to assume the mechanic didn't put this back together correctly? To be fair, I've got just over 208,000 miles on this beast. Never replaced any suspension components until I had the outer tie rod ends done - this as a result of my car starting to eat through tires (wearing the inner front) and not keeping an alignment.
Lastly, anyone recommend a good AUDI mechanic in Pasadena, CA?
Thank you in advance for your feedback in insight. Long time reader, first time poster...

silverd2

The nut you need is part # 4D0 407 644 A...or any quality "shouldered M12x1.5 nut"....should be torqued to 74 ft lbs...that's VERY tight and should never have backed off.

I've NEVER seen this before..in fact, when removing this arm connection, a special tool is usually needed to pop it free for removal...usually almost seized in place with the nut removed...no telling how long it was missing.

And, no...replacing tie rod ends should never involve removing that nut...no need.

I have no clue why that would come off, unless it was never torqued down or even replaced...maybe during a previous repair or replacement of that arm (Guide link).

silverd2

P.S. >>>>

NODB8

Wow. Thank you for the details. Sorry, I know I posted this on two forums. Had no idea I'd get such expedient and thorough replies. You guys RULE!

NODB8

Found this in the parking garage next to the speed bump - decided to go have a look tonight, and low and behold...

I think this is it? Should I use an compound like locktite?

sonata54

That is most definitely the nut, as long as it's torqued to it's specification you should be fine. This is a tapered end and is usually one of the harder ones to remove so i'm surprised that it ever popped out.

NODB8

Luckily, went back together fine. Amazing that I was able to find the original nut in the parking garage next to the speed bump. Threads weren't stripped or anything.

After getting it on a lift and looking around, several of the suspension bushings look pretty worn out. Is it better to replace the complete suspension arms, or can one replace just the bushings?
Any insight and feedback is appreciated.

sonata54

It's easier(and better) to change the whole arms. Usually when a couple of arms go bad, the rest follow shortly. There are a couple of arms that seldom get worn out but it is much cheaper to buy a whole set than to buy each arm individually. You can find complete sets on Ebay for around $250 vs. each arm for around $500.

Just make sure when buying sets that you get the right year. The control arm that popped out on your car has a different length in 97-99 and 00-03 models.

Adjuster

I have replaced the left upper arms on my 2001 S8, and have them to do still on the right front. There are 4 arms per side in this suspension design, and 4 ball joints that connect up to the knuckle.(That's the part your axle/wheel/brake is attached too, that goes up and down, that motion is dampened by the shock and spring that is bolted as you can see, to the lower control arm that popped loose on your car.)

I found the best prices on complete arms is at rockauto.com. You can get just the bushings, but you have to remove the arms, press out the old bushings, press in the new ones, and hope your ball joints are not bad.. I figure it's just better to buy the complete arms and go with that.

On my car, the upper "twisted" or rear arm bushings were wiped out at only 75,000 miles. They were rubbing on the cradle that bolts them into the upper strut tower. It's a complex process to replace them, but not impossible, just complex. You have to pre-load/position the rear arm bushing, or it will be destroyed in short order if it's out of position. (Shooting for the bushing to be NOT twisted up with car on the ground, but it will be twisted when it put it together and the suspension is hanging loose.) Paul W. has a nice write up on how to replace them.

On my car, the longer, front or straight upper arm was fine, but I replaced them while I was in there anyway. The rear bushings were/are totally shot, and resulted in too much negative camber, that wore out the inside edges of the tires.