Alignment nightmare

​​​​​​​I think I have a big problem, and in an area that I don't have a lot of expertise. Little history. "02 C2, with 169,000 miles (original motor, not that it's relevant to this issue). I've owned this car for 6 years and put 70,000 miles on it. It was aligned shortly before I bought it, and although I've been through several sets of tires, they have all worn as expected. A few months ago I had new shocks and springs installed but wanted to wait a few months until I got new tires before I got it aligned. A couple of weeks ago I had the car in to a Porsche Indy that I have used several times, to get some things taken care of (new water pump, among others). While there I asked if they had anybody they recommended for alignments. They used a local tire place, that I believe has a good reputation, and at my request they said they would arrange to get it over there and back to the shop while they had my car. (Both shops are about 30 miles from me, so not super convenient.) They didn't charge me anything for this. Got the car back and it seemed different, but OK. However my steering wheel, which was always a little off center, was now cocked at least a 1/4 turn to the right. Annoying, but figured if the alignment was good I'd just pop the wheel off and re-center it. Took at trip of about 250 miles. On the way it seemed OK, but on the way back, whole other story. I posted in another thread about when I came upon about 15 miles of new concrete interstate, much of it etched, the car was very hard to control at 80 mph, and I had to slow down to 65 until the pavement went back to tar. Immediately checked my tire pressures and all were OK, so I drove home, but carefully. Called the Indy and he suggested I call the tire place, which I did. Guy said he would be glad to check everything over. I asked for an appointment, since it was a drive for me, and I was definitely going to wait. "Not necessary" was his reply. Bring it in anytime and they'd take care of me. I said I'd be in the next day or two. Took it next morning, arriving at 8:45 AM. Mgr I spoke to was off that day! Told my whole story again and the guy said they'd try to work me in right away. 90 minutes later I asked for my keys and told him I wasn't waiting any longer. He asked me if I wanted to make an appointment, which really ticked me off since that's what I wanted the first time. I reminded him I'd already driven 30 miles that morning, and wouldn't make the trip again. At that point I'd lost any confidence in them and decided to go elsewhere. Turns out that was a good decision. On the recommendation of a Porsche driving friend, I went to another place earlier this week. I didn't tell them where I'd been, but told them someone else had tried to align it and clearly something was wrong. He offered to print out the alignment specs, before and after, so I could compare. However he barely had it on the lift when he called me into the bay. Just checking things over visually he immediately found one of the front tie rod "jam nuts" (that's what I've always called them) hanging loose, about 1/2" backed off where it should have been. Not a good sign. (And I have a picture.) But when he really got into it he discovered a bigger problem. (And this is where my tech knowledge is very thin.) The Centrix adjustments on both rear wheels have been damaged, and it looks recent. He thinks someone tried to adjust them without taking the engine weight off. He was able to manipulate them a little, but not much. It appears the centrix assembly is part of the rear subframe, necessitating replacement of this part(s). I called the Indy shop to discuss this, but they're closed this week, so I'm waiting until Monday. To be clear, I do not hold them responsible in any way for this. The tire dealer is where the problem is, but I want to talk to my Indy first, to see if he might have enough sway with the tire shop to help. I'm not optimistic though. The fact that the jam nut was left loose and the steering wheel was so badly misaligned (fixed with my alignment earlier this week!) add credence to my side of things, but I'm guessing they'll admit to nothing and simply refund my money. That's likely a pittance for what it's going to cost me. Any suggestions welcome, or if you can help me better understand the mechanics of the centrix system that would be great too.

All of this sounds like a major PITA. Good luck with this.

centrix sounds like you mean eccentric. What is wrong with it? The only thing in the subframe is an oblong hole, so not a hell of a lot to go wrong with the subframe itself. You may just nee eccentric bolts. pics?

When you say Centrix, do you mean the eccentric? It is very doubtful the subframe is damaged. If it is, the last one I had to replace I bought off eBay for $100. What probably happened is they tried to loosen the eccentric bolt from bolt side instead of the nut. There is a groove in the bolt and tooth in the washer. This causes the washer to dig into the bolt and booger the bolt. This is very common. A new eccentric bolt will solve this issue fairly easily.

I could be wrong on the terminology. Sorry! Wish I had snapped a pic of the rear suspension, but sadly didn't.

Is there anything to what this last alignment guy said about taking the engine weight off things to prevent this from happening? Just trying to get my facts straight.

No. I use 3 or 4 loose sheets of a magazine between my tire and scale so that the tire will swivel when I adjust the alignment with the full weight of the car on it.

Here's a picture of the eccentric bolt. photo536.jpg Here's a picture of the two eccentric bolts, on for adjusting toe, one for camber. The oblong ends cause them to move forward or back in the subframe when you turn them. But the nuts have to be loosened obviously to do it. photo230.jpg

Thanks! Very helpful!

When I disassembled my rear suspension recently I found that both of the rear toe eccentrics were damaged....it appeared someone took an impact wrench to them. They were gouged where they had tried to spin on the eccentric washer at the other end. This made removing them very difficult (to replace them w/ new ones). I could see an alignment shop who does not know these cars doing that...Look at Slakker's photo above you see the eccentric cam is one piece with the bolt.

If you don't do your own labor, then it may end up being cheaper to buy lockout hardware and purchase some adjustable rear track arms to permit the toe adjustment if that's the part they beat up. I've had to replace the side member due to not being able to reach proper alignment due to wearing out of the surface the eccentric rubs on. In hindsight, I should have locked it out and installed adjustable arms.

I've had two eccentric bolts that were damaged on the roller I'm working on. If it isn't too bad, you can carefully file the threads where the damage is so that they are not sticking out beyond the rest of the threads. This will allow it to slide in/out again. As nick stated, an impact wrench can cause the damage. Or as I found out my very first time, if you hold the nut and try to looses the bolt, you will get the same result.

I can't thank you guys enough! Great pics!!! I feel very relieved at this point, and much better able to discuss my car's situation to the tire shop. I doubt they're going to own up to doing it, but by the same token the repair doesn't look near as difficult as I first imagined. More than once I have turned to the 996 forum with a question, and never been disappointed. Thanks again!

I think the comment about taking the engine weight off is that the eccentric can move the arm in/out easily without load on it. If the car is sitting on an alignment rack with a slide plate of some sort under the tires, probably not necessary to raise the car up to move the eccentric but otherwise it sounds like a good idea to do so. Problem is, if the tire won't slide when you try to adjust it, and you lift the car to adjust, it also won't slide after you adjust it and drop the car back down. You would have to move the car forward and back several times to get the suspension back in a position where you can check the results of your adjustment.