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BMW Cannot Align My E90
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12-23-2013, 07:35 AM | #23 | |
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Here are the basics: A car will pull to the side with the more positive camber. Not the least amount of camber. A car will pull to the side with the least amount of caster. Without a caster reading you cannot tell anything by these pics. Last edited by john231; 12-23-2013 at 08:22 AM.. |
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12-24-2013, 04:35 PM | #24 | |
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If one side is less negative than the other, wouldn't that side be more positive? Being most Bimmers run negative chamber, wouldn't it be safe to say that the less negative side is more positive than the other? I'd say you can tell a lot by OP's sheet, but the main thing you can tell is the person doing the alignment said "caster isn't adjustable anyways, so I'll just do a half ass job, not swing caster, just bring spec's into 'green,' & not test drive afterwards to check to see if it tracks straight." |
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12-26-2013, 02:07 PM | #25 | |
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The OP has a left side of -.8 and a right of -.4. If we are going by the "cars pulling to the least amount of camber" statement, this car would be pulling left because -.8 in this case IS the least amount of camber. -.4 is more positive. Having said all that, and if we knew the caster was good on each side, I still don't think that a .4 cross camber difference would make this car "pull hard" to the right. I've seen much worse go laser straight down the road. I also see what you mean about the tech blowing off measuring for caster since it is not adjustable. That is just lazy especially since caster is a HUGE part of how a car handles. So my whole point is, we don't know what the caster is, so we can't blame camber yet. If we knew for example that the caster was equal (or very close) on the right and left, I'd probably road test the hell out of this car, check the front end all over again for worn parts etc., check air pressure and rotate the tires. Road test again, and if needed I would set up on the aligner and double check everything. Maybe then would I tweak the camber a little positive on the left and a little more negative on the right hoping to compensate for the right side pull. I would do this and still keep the camber angles within specs of course. I know people might think that I'm going nuts over this missing caster, but it is something we need to know. Talk to you later. Funny thing is that I have a Pontiac Torrent on the rack now that has perfect camber but the left front caster is 2.1 and the right caster is 3.3. A cross caster of -1.2. I road tested the car before I set it up and it drives perfect. By looking at these numbers I'd expect some kind of pull to the left... Go figure. (it was in an accident so something is bent somewhere.) Later. Last edited by john231; 12-27-2013 at 07:15 AM.. |
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12-28-2013, 05:14 PM | #26 |
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John231
We must be having a really hard time understanding each other. If a person says they have MORE chamber on one side than the other, the side with MORE chamber has a more negative chamber setting. Correct? -.4 chamber is LESS negative chamber than -.8 we, can agree on this? There for -.8 is considered to have MORE chamber? So if we go back to the Dixie cup idea, the mouth side of the cup would be on the right & the bottom would be on the left, since -.4 is less negative chamber than -.8 Help me out if I’m explaining this wrong please! You obviously have some experience with doing alignments Total side note, anyone know if swapping strut hats from side to side will give more chamber like it did on the E46’S? My M3 is all stock except for brake pads & tires, but I wouldn’t mind running more “free” negative chamber. I think it gave you almost -2 on the E46’s |
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12-28-2013, 08:41 PM | #27 |
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I actually have my alignments done at firestone, they do a lifetime for about 150 bucks which means you can take it in as often as you want. I think that encourages them to get it perfect the first time. They did mine, road tested the car and then fine tuned it. All in they spent about 2 hours getting it perfect. They suggest I bring it in twice a year to get it checked. The dealer did it a few years ago and it was never quite right and cost 200 bucks a pop
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12-29-2013, 02:49 PM | #28 |
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I worked for BMW for some time and I had this issue come up countless times.
Yes. Crown in the road is typically the main cause. Sometimes you can't even see it and there is a slight crown. However. In addition to the crown. For safety specs. Most shops align it just a degree to the right so that for safety you can't a) drive straight on its own without driver attention and b) veer left into on coming traffic. The reason it veers right is to in conditions when you are not paying attention the safety bumps off the right side of the lane or a curb will alert your attention. Not trying to go into so much detail but I hope one can understand what I'm saying here. I myself am frustrated they do this and I even tell them. "F*k safety! Just align it straight. No drift right" but then they tell me "well you have a bit of wear on your tire causing it not to be completely perfect" etc... Anyway. This is my two cents and I hope this helps. I was no stranger to the BMW "bullshit" we had to feed to the customers. Haha! |
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12-30-2013, 02:58 PM | #29 | ||
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For example: Left side has .5 camber, Right side has .2 camber. In this case the Left has more camber. Same goes for if both sides have negative camber, like the OP case. Left side has -.8, Right side has -.4. The right side has more camber. Quote:
The -.8 is "more negative" camber than -.4. If we just asked "which one has the least amount of camber?" The answer would be -.8 All the confusion is how we are putting this into words, and when (or where) we are using "more (most) negative camber, less (least) negative camber." Think of a number line, this is how the Hunter Alignment School taught us. -8 -7 -6 -5 -4 -3 -2 -1 0 +1 +2 +3 +4 +5 +6 +7 +8 (-8) -7 -6 (-4) -3 -2 -1 0 +1 +2 +3 +4 +5 +6 +7 +8 The -8 is the number with the "most negative" camber in this case. The -4 is closer to the positive side of the number line so it has "less negative" camber than -8. The -4 is more positive than -8. or the -4 has more camber than the -8. Hope this makes sense. . |
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01-03-2014, 07:53 PM | #30 | |
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And although the caster is missing and is very important. It likely wouldn't help here. I can almost bet you that the steering wheel is just off and the tech did a poor job setting toe. And a .4 camber split wont cause a pull since both sides are negitive. If it was -.2 and +.2 then yes it would likely pull as the wheels would sit like this /----/ In other words i can Set toe to match perfectly to specs and have the steering wheel at the 3 o clock position. The print out would show a perfect alignment. This is often the case with most "pulls" that people have post alignment. |
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