AWESOME, looks like a deal. Tirerack has them for 232. Imagine this would be cheaper than going to a body shop like the alignment shop recommended, and less headache than dealing with Honda, a buddy and I could have this swapped out in half a day. Thanks for the helpful info starman!

 

From the OP's first posting (emphasis mine):

We've been running on the "incorrect" upper control arms since day one, still have them, and our OEM Bridgestone Insignia's could not be more uniformly worn, at 85000km's (minus maybe 10000km when we used snow tires, so far). We still have at least 5/32" remaining tread depth, all around, and no sign of uneven wear.

The original control arms are slightly greater negative camber, I assume. But it's not a night-and-day difference I would think. They're not "incorrect", just a slightly different configuration. Part of the issue could also be manufacturing tolerances, ie: some control arms are closer to one end of the tolerance than others. Dunno.

FWIW: Honda's no help. They brand the "new" control arms with a "C". Again just assuming, it probably stands for Correct, Corrected.

 

Well, I double checked the control arms and they are both definitely marked "C". Only the insides of the tires that were on the rear are serrated now...the tires that were on the front are worn nice and smooth. Oh well, i'll live with the noise and vibration for now and hope they wear down smooth...if not, i'll have scoops on the insides of the front tires to tear through the snow this winter before I throw these ones out!

Moral of the story here, even with the corrected control arms, ROTATE ROTATE ROTATE! 9000 miles was too long for these soft tires, should have rotated every oil change! Extrapolate that on harder all season tires and make sure you rotate every other oil change at least!

 

Your welcome, hopefully they will work for you.
My take on the "C" on the arms is that they are revision 3.

 

fyi, I had my harder hydroedges remounted last weekend because the other tires were unlivable. Tire shop mounted them back where they took them off and I had a lot of noise coming out of the rear. Buddy and I rotated them yesterday to the front, and I observed the same inside serrated tire wear on these tires as well, post TSB control arm fix. Noise and vibration and moved to the front.

ROTATE ROTATE ROTATE!

 

My '08 HCH has the noisy tire problem due to the improper rear camber. Interestingly, both my rear upper control arms have the "C" markings but these markings have different fonts one side from the other! The right side has a more "serif" font and has a within-spec -0.7deg camber. Now the other side has a much simpler-looking "C" and this one has a -1.7deg camber! I haven't swapped out tires but I wouldn't be surprised if the noise would only be coming from that left side...

Here is my theory about those "C" stamped upper control arms that are still defective:
Honda had to produce and replace alot of those control arms. They probably had an extensive stock of those "defective" control arms (themselves or their suppliers). My guess is they probably went through their old stock and measured them. Every one that was even marginally within-spec of the new numbers, were also stamped with a "C" and returned to the parts bin. This would explain why my two control arms have different camber values and different "C" markings on them to go along.

Honda is currently studying my case and will come back with an answer soon but I'm already foreseeing they will tell me the parts are the correct ones with the "C" and are within (their very loose) specs. In that case, I will purchase some adjustable control arms from the after-market before I go buying new tires after only 36,000KMs.

 

My uneducated guess would be that the toe adjustment is the culprit for scalloping. Wouldn't excessive camber just accelerate wear on inner or outer edge.

If your tires are excessively toed, they're constantly trying to roll along the road, but getting pulled laterally (by the agressive toe setting), towards or away from the vehicle's center, and then having to do micro-jumps to relieve this pull. The cadence of these jumps is evident in the scalloped wear spacing.

Whew! Feel free to shoot holes in the above.

 

Make sure they use the new alignment spec. on the TSB. (camber 0 to -1.5 deg). So the -1.7deg is out of spec. the -0.7deg is correct arm to use.

 

I have the alignment figures from before it was re-aligned:

Camber: F/L: +0.5 F/R: -0.6
R/L: -1.7 R/R: -0.8

Caster: F/L: +6.4 F/R: +6.9

Toe: F/L: -0.04 F/R: -0.22 (toe out)
R/L: +0.17 R/R: +0.21 (toe in)

Silly me, I just assumed that when I bought my car new, part of the "preparation" fees were for the alignment of the car. Apparently not.

My tires are now pretty much intolerable so I will replace them come spring time. I'd just hate to buy new tires to have them go bad again within a year or so. For sure I need to have it properly aligned.

My understanding of the suspension geometry (from what I read on the internet) is that when the camber is too pronounced, and the suspension goes down (due to loading the car), the toe goes in even more and makes the situation even worse.

I am seriously considering getting adjustable upper control arms. Seems to me that being able to adjust the camber is a good thing in any case.

Daniel

 

I think preparation is largely cosmetic, taking off protective films and coatings, plus some cursory checks, stuff like check of tire pressures, fluid level checks and so on. Mostly the kind of stuff you do yourself.

$1500, thanks very much. Oh, and there's the "documentation" fee, and the "environmental" charges. And so-and-so in sales in getting hitched, so we'd like you to chip in for a...

MSantos has mentioned that he makes a point of getting a 4 wheel alignment check done on all his new vehicles, fwiw.