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Front camber imbalance WAY out!


M635uk

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Ok, love my Boxster but previously had a bump that required a new rear passenger quarter panel and bumper.  Very limited damage so I bought it back from the insurance company and put it back on the road.

that was some years ago but recently had a full alignment do one as the pic shows below.  As you can see the front camber results are bizarre, plus 2 deg one side minus 3 the other, obviously ran out of adjustment on the slots on the mount so a bit stumped on next steps.  I can correct with  adjustable front control arms but is seems to me that the front subframe is misaligned, or the chassis bent (although all other readings are great and the initial rear settings weren’t too bad at all.), or something else is bent like strut housing, but to the naked eye I can’t see anything obvious.  Caster is fine too.

Using basic trigonometry it would suggest the arms/strut or front subframe is 30mm shifted to the right, looking at it from underneath that can’t be the case, subframe seems centrally located..  Car drives very well!  And my front tyres have lasted 22k miles. I have rechecked the camber at home with a simple camber tool and they are correct.

Any suggestions would be appreciated before I pay £650 for adjustable front arms, thanks.

C096CC15-64F5-44C5-B02A-DE5A547DA470.jpeg

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The turret tops are slotted in the shell as standard so some adjustment is achievable, however the factory standard is 10' negative camber +/- 30' so i.e. 20' positive camber to 40' max negative camber.  2° or more is way, way out to factory, but some have recommended getting as close to 3° as possible for added steering response and feel.  When I put mine to max on the turret slots I got similar readings to you, so pulled one side back to match them as close as possible, however fine adjustment is very tricky unless you got to an adjustable top mount.

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If you really have positive camber on one wheel and negative on the other it should look quite obvious. Given that you say the car drives ok I'd suggest getting another alignment check elsewhere. 

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Front left definitely has positive camber, visible to the naked eye on a flat surface. And also shows positive 2 deg with camber bubble tool.  Maybe left front wheel got whacked, but that wouldn’t account for neg camber on front right.  Unless that got whacked too.

 

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Are you certain the front subframe is centrally mounted?

Have heard of these being moved over time or by a bump.
Sometimes they’re removed for some other job and not properly replaced or even if they are I think they’re fixed with single use stretch bolts. 

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I just looked at a bigger pic of your print out. Wow I'm amazed you say it drive well! You've got almost 6 degrees variation in the front camber. Have any of the suspension arms been replaced, something must be bent surely. 

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3 hours ago, ½cwt said:

The turret tops are slotted in the shell as standard so some adjustment is achievable, however the factory standard is 10' negative camber +/- 30' so i.e. 20' positive camber to 40' max negative camber.  2° or more is way, way out to factory, but some have recommended getting as close to 3° as possible for added steering response and feel.  When I put mine to max on the turret slots I got similar readings to you, so pulled one side back to match them as close as possible, however fine adjustment is very tricky unless you got to an adjustable top mount.

Well I can try adjusting to see what the impact is, but with I don’t think it will turn my 2 deg positive to negative, if fact it is at the end of its adjustment now.  Thanks. 

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18 minutes ago, edc said:

I just looked at a bigger pic of your print out. Wow I'm amazed you say it drive well! You've got almost 6 degrees variation in the front camber. Have any of the suspension arms been replaced, something must be bent surely. 

Yep 6 degrees difference in front camber and yes it drives well, but I don’t drive like a loon so don’t approach the limits.  Drives straight, no pull.  
coming to the conclusion something is bent as you say, just trying to work out specifically which bit.  I bought at 57k mikes with 3 previous owners, no previous accidents apart my my mishap at 74k miles.  At 96k now and not getting through tyres.  Perhaps camber imbalance isn’t that stressful on tyres!   
 

all coffin arms replaced by porsche at 53k miles and alignment redone according to the invoice.

Edited by M635uk
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Another thought, I did the 987 air box mod 2 years ago and it required the engine to be lifted, maybe I set the engine back incorrectly but I struggle to see how that would show as front camber imbalance of 6 deg?

Edited by M635uk
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Lifting the engine would show in the rear more wouldn't it?

Have you had the struts or hub off? Is the left one bent and shunted the subframe to the right a tad? Big pot hole or understeer into a kerb? 

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9 minutes ago, edc said:

Lifting the engine would show in the rear more wouldn't it?

Have you had the struts or hub off? Is the left one bent and shunted the subframe to the right a tad? Big pot hole or understeer into a kerb? 

Think I need to get the measuring tape out and start looking for the culprit.  I had the same thought re any anomalies with engine location being seen in the rear settings.

Never had struts or hub off,  pot holes yes, 180 miles Peak District run east to west every week for the last 5 years.   Understeer into Kerb, no, not in my ownership.  
 

I appreciate the number and speed of responses on here.  I run an e34 BMW Alpina replica as well and responses on that forum take days!  

Edited by M635uk
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Ok had a really good look under the front subframe this morning with the car jacked up in the air and petrol tank cover removed.  The subframe seems to be very well centralised and there is no way you could move it 30mm laterally to account for the camber imbalance as it would hit the inner wing flanges.  Also no obvious bend in the control arms, difficult to say for the struts and the front hub assemblies.  Maybe I need to take them off to get a better view of them.  Still a bit baffling as to what could be the cause of the 6 deg camber imbalance across the front wheels.

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Just a thought - is there any way the static camber is different to the dynamic camber?

What I’m getting at is this: Is there a bushing or some other joint that could be deformed/failed in such a way that it allows the measured camber when stationary but when under dynamic load (driving) corrects the camber?

Am only thinking along these lines because the tyre wear you're describing doesn’t seem to fit with the camber you’re measuring.

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2 hours ago, map said:

Just a thought - is there any way the static camber is different to the dynamic camber?

What I’m getting at is this: Is there a bushing or some other joint that could be deformed/failed in such a way that it allows the measured camber when stationary but when under dynamic load (driving) corrects the camber?

Am only thinking along these lines because the tyre wear you're describing doesn’t seem to fit with the camber you’re measuring.

Ok, just checked all bushes, they are all in excellent condition.  So not a sagging or knackered bush.

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6 minutes ago, M635uk said:

I think I need to take the strut and hub assembly off and have a closer look.  Failing that  it may be a twisted chassis?

Unlikely the subframe is substantial and well secured plus I think you would see any distortion, however strut out and a straight edge against in several planes may show up the culprit 

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3 minutes ago, bally4563 said:

Unlikely the subframe is substantial and well secured plus I think you would see any distortion, however strut out and a straight edge against in several planes may show up the culprit 

Looks like my weekend job…need to resolve this.  It’s driving me bonkers.😊

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6 minutes ago, M635uk said:

Looks like my weekend job…need to resolve this.  It’s driving me bonkers.😊

I can remember reading an article some moons ago where a well respected indi could not get it to align, and after exhaustive investigation, found the strut was bent and from memory it was not much circa 5-10 degrees, but it showed with a straight edge, just at the point it came out of the hub, so you would need to remove it for inspection, otherwise you would never notice.   Good luck

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5 minutes ago, bally4563 said:

I can remember reading an article some moons ago where a well respected indi could not get it to align, and after exhaustive investigation, found the strut was bent and from memory it was not much circa 5-10 degrees, but it showed with a straight edge, just at the point it came out of the hub, so you would need to remove it for inspection, otherwise you would never notice.   Good luck

Thanks,  measure twice…or 4 times 😊

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16 minutes ago, M635uk said:

Some photos, not sure they help.

two showing top mounts at max to try to counter camber issue, no more to go.

one showing strut assembly

2683F2EF-F470-41AB-A448-A6450042653A.jpeg

Pics are deceptive, but that does look like is pointing towards the vicar

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