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BMW 3-Series (E90 E92) Forum
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Alignment questions
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08-19-2010, 04:42 PM | #1 |
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Alignment questions
Hello,
I have a 2007 E92 328i with sports package, no active steering. When my car had about 15,000 mi I brought it into the dealer because of severe tramlining, unstableness, and very light steering at high speeds. They told me to go get an alignment, that would fix it. I got an alignment at a different shop because I felt the dealer was too high. They gave me a printout from their Hunter GSP 9700 rack showing everything was well within spec. Fast forward tens of thousands of miles later, I notice my right front tire is wearing on the shoulder heavily, so I go get it aligned again. I get a printout again, showing everything was within spec. I had my car in service and they gave me a 2010 328i with sports package, and the loaner drove completely different. Much more stable, tracked the road much better, and just better in every way. This car has the same tires, suspension, and everything so I thought this was unacceptable and called the dealer and insisted they take a look at it. Their conclusion was there was nothing wrong and I need new tires (the tread is at 6/32" using their own tool measured by their shop foreman - ridiculous). I took it back in for the same reason and said I have an alignment, I can produce the printout, it's done on the same rack as you. The shop foreman comes out and looks under my hood and states "I promise you this car has never been aligned before." His claim is that if there are pins present (shown in pictures below) on the struts, then the camber cannot be adjusted. Once camber is adjusted, the pins cannot be replaced. I thought this was a stupid explanation, so I tried getting more details, and long story short he offered an alignment for free. I pick the car up and he shows me a printout showing before and after alignment, and of course before shows everything was way out of this world off and after is perfect. The first thing I do is open the hood and what do you know, the pins are there. I get the shop foreman and ask him why I was lied to, and he gives me this explanation that putting the rear in alignment "pulls the front" in alignment as well. I still don't understand how the front right wheel knows if the rear is misaligned or not. Can anyone clarify this for me? Also, does anyone know what these pins, which are circled in red in the pictures below are for? And when an alignment is performed, do the large screws on top of the strut have to be loosened? Judging by the condition of the dust/dirt, there was certainly nothing on top of the strut ever touched. Here are the before/after alignment specs in the front. before: left camber: -0.16* right camber: -0.90* left caster: 7.18* right caster: 7.17* left toe: 0.17* right toe: 0.20* total toe: 0.38* steer ahead: 0.02* after: left camber: -0.58* right camber: -0.50* left caster: 7.33* right caster: 7.12* left toe: 0.10* right toe: 0.11* total toe: 0.21* steer ahead: 0.01* Is this difference possible without adjusting the front and only adjusting the rear? This almost seems like a stupid question, but I don't really know how alignment racks work. I really hope I can get a good answer - I'm getting frustrated as no shops, dealer included, seem trustworthy. I just want a decent alignment done. Thanks for any responses. |
08-19-2010, 04:56 PM | #2 |
Second Lieutenant
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i can't get the pictures to attach for some reason, so here they are.
http://bellsouthpwp.net/s/i/simon308/img00097.jpg http://bellsouthpwp.net/s/i/simon308/img00099.jpg |
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08-19-2010, 05:11 PM | #3 |
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Drives: '05 E90 330i Manual
Join Date: Aug 2010
Location: Cape Town, South Africa
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Don't have very many answers, but a few things to consider:
Toe-in which is basically a positive toe value aids front wheels stability at the sacrifice of cornering sharpness, and more related to your case, tyre wear on the shoulders. And being that you drive on the right hand side of the road where the road camber is to the right, the right tyres tend to get 'eaten' more on their shoulders compared to the left hand side. Normally you would want the toe to be set to zero which is then referred to as neutral. I presume you have run-flats on, which are well known to tramline - but since you have had another similar car to drive that feels totally different it could still be an alignment issue which I've heard is quite crucial on the E90/92's. Hopefully other members here will be able to help with more info... Philip |
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08-19-2010, 05:13 PM | #4 | |
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Drives: '05 E90 330i Manual
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08-19-2010, 07:01 PM | #5 | |
LSD - No, you're not seeing things
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Quote:
I think you have been bent over by the dealer here Nothing you alter on the rear geo can affect the physical camber/toe/caster on the front. The stats show a camber change up front, but yes to do that you must shift the top of the strut a little. The struts have the pin you pointed to so when its built the strut locates in the correct position - the three nuts on the strut are then tightened. To alter front camber you have to drill out those two pins, loosen the three nuts and move the whole thing. If you need a lot of camber adjuatment you may need to elongate the holes in the chassis (turret tops) and that requires the front suspension to be dropped out of the way. The rear camber is adjusted by an eccentric bolt on a suspension arm btw. Either they lied, or have NO idea how to run that geometry rig they have. A Hunter GSP9700 is a tyre balancing rig too, not a geometry rig - maybe you got the wrong name here? Last edited by m1bjr; 08-19-2010 at 07:07 PM.. |
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08-19-2010, 11:17 PM | #6 |
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m1bjr, you're right. I guess I do have the name of the machine wrong. I really appreciate your info - just as I suspected I was lied to. I really don't appreciate this and I'm wondering if I'll ever find a shop that will actually align my car.
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