tire wear / alignment issue

[rbboxter]

I have a 1999 boxter. I am experiencing extreme tire wear. It is related to the rear alignment. The rear toe in / toe out control arms are too long from the factory. There does not appear to be enough adjustment on the cams to set the toe properly without having severe negative camber.

Does anyone know if POrsche has a service bulletin out on this or is there a replacement control arm available that is shorter than orginal?

[jfmillr]

I have the same problem. Mainly as a result of putting lower springs and new racing shocks on. it changes my height by about 3 inches and as a result am slightly toed out in the rear tires. Actually it appears the left rear tires I can get aligned by the right rear cant be adjusted enough. Porsche has given me no remedy upon inquring with the dealership other then matching the toe for the left rear to match the rear rear as far as it will come in. Hopefully you can make some sense of it all.

[Bob MI]

It appears i have the same problem and it appears in the right rear. The Porsceh dealer gave me the OK on the alienment but a local guy (non porsche said he could get it into alienement).

[jfmillr]

Well in my experience with having the suspension lowered its the same right rear tire that the camber(I think thts what he called it) could not adjust the wheel in any further. So we matched the left rear to as far as we could get the right rear to. I think it is called having negative camber on both rear wheels. Good for handling but bad for tire longevity.

[smokey-burnout]

My 99 boxster also wouldnt align properly even with the toe adjusters all the way in it was still toed in. I had to give it a lot of neg. camber to get the toe to zero out. The tire wear problem started a about 22,000 mi. after the dealer replace the Rear main seal. I talked to a buddy of mine who is a porsche tech, I asked him what would happen if the car was set down on its weight, off the lift , while the trans and the cross members were out. He confirmed what i suspected that the tolerances in the bolt holes and the cars suspension not being tied together ,would splay the control arms out. And it would not bolt up in the same position it was before . My car also has the sports suspension which compounds the neg. camber issue even more as the car sits a little lower and ads a bit more camber gain compared to the base suspension .To fix the problem required me to loosen the crossmember bolts and the aluminum struts and pan under the trans, and pull everything together with a cable puller ,the tighten all the bolts and realign the camber an toe. So far I have 30,000 plus on a set of yokohama 255/40zr17 avs tires and the still have tons of tread left. These are light cars and tires should last a lot longer than a heavy car. Also find a good alignment shop that understands how to properly align a porsche suspension.

[John V]

How much camber is excessive? My '00 S will align to zero rear toe with -1.4 degrees of negative camber. If you want less negative camber than that, you have to add toe-in.

The USA sport chassis (030) is no lower than the standard suspension so it aligns exactly the same.

There is a bit of slop in the bolt holes. In addition to turning the cams to align the car how you want, you need to toe the wheels out as much as possible manually (by pulling) with the toe adjusters loose. Then tighten the toe adjusters and use the camber adjustment cams to dial the toe back to zero. This will give you minimum negative camber and zero toe.

[insite]

Originally Posted by John V

Then tighten the toe adjusters and use the camber adjustment cams to dial the toe back to zero. This will give you minimum negative camber and zero toe.

i'm in the same boat as these guys; my car is lowered (RoW M030). the least camber i can run at zero toe is -2.25 degrees. for those looking for a solution, the TRG or Tarrett Engineering toe links will correct this problem. unfortunately, they are $500 a set.

[TriGem2k]

Ill chime in as I JUST had my alignment done on my car last Friday.

In order for my toe to be within spec my Camber is set to 2.14 on each side.

It is true that the rear right wheel has a harder time coming into spec. Not sure why but that is what my mechanic told me.

Having shorter springs on the car really does take its tolls on your tires. For me its not really an issue as I don't mind replacing rear tires every 3-5k miles.

I had the mechanic print out the spec sheet of my alignment, I will post it as soon as I get it scanned.

[Adam]

Wow, this thread is back from the dead!