Advice requested from those of you who have successfully checked camber at home

Pythagorus' theorem -, or better yet, trigonometry. Or a triangle calculator like

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Solve a triangle. You know (from your measurements) the base of the triangle (distance from spindle) and the height (difference between the projected line and "straight"), or the base and 2 angles (the desired angle and 90 degrees) to calculate the height. One way tells you what angle you have, the other gives you the distance measurement you WANT.

Your biggest problem is getting your head around all the concepts.

On some vehicles it CAN be that simple -- On others it is definitely a wee bit more complex, but you have the idea.

And the length of the studs/bolts gets critical - not to mention it works best with 4 or 6 studs - not so good on odd numbers like the common 5, or the less common 3 stud wheels.

Reply to
clare
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There is a saying about Bimmers. If you have to ask how much - for anything - you can't afford to drive a bimmer.. There are enough things that can go wrong in the front end of one of those kraut-wagons that I think you are definitely being penny wise and pound foolish trying to save $100 on the maintenance of a late model Bimmer. Don't be such a cheap-ass. - or drive a Chevy.

You want to know if anything is worn or bent - and measuring CASTER is required as well to know. You really don't have your head around the concepts well enough to understand WHY an alignment check should be done properly. Your "quick check" is just that - and if you are at all in tune with your car as a driver you will know there is something wrong just as well by simply driving the car. If you are not "in tune with the car" the Bimmer is wasted on you --- (as it is on the vast majority of Bimmer owners)

Reply to
clare

If you are going to measure the toe with a string, you may as well forget about it. You can NOT get enough accuracy or repeatability to determine if the toe is correct or not. Without pro equipment, to get that granular in your measurement you NEED to extend your measurements

5 or 10 feet and measure with a goor steel tape measure, or extend the displaced centerline accurately and measure with a steel rule. Using the simple tape measure will give you the total toe - which will be double the specified toe per wheel, and will not tell you if you are off-center.
Reply to
clare

That depends whether it is at 12.5 inches, 12.5 feet, or 12.5 miles....... You REALLY need to study your high-school math.

Reply to
clare

Following that statement to the logical next step, here is a representiative track for my sedan from this thread:

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That photo says that the track is:

- Front Track Width = 1512 mm

- Rear Track Width = 1526 mm

So now what's 1/60th of a degree, in millimeters?

Reply to
John Harmon

You have a misunderstanding, to figure millimeter or inches, you need to have two lines that are connected like a below,

l****/ l / l / l / l/ The angle between l and /, we will call 1/60 of a degree, the **** is the millimeters or inches, BUT, the quantity of millimeters or inches depends on the length of l, as you can see the longer l the larger **** will be. But the angle stays the same.

Use the link below may help you see it.

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I put in a 1 degree angle for (angle a) and 16" for (side B) Then hit calculate to find (side a). This says you need 0.279" of tilt top to bottom on a 16" wheel. Note: this triangle is rotated 90* to your wheel. So take that into account when thinking about the calculation. Bottom line, for a 1 degree angle you need a tilt of 0.279" over 16". That's measurable, but you need a post 90* off the floor to measure from. Second note: Side (a) the tilt at the top (mm or inches), Side (b) is perpendicular to the floor, Side (c) would be the tilt of the wheel. Angle (a) is the degrees of the angle you set.

Mikek

Reply to
amdx

Sheesh, you don't translate angular measurements into linear ones. An angle isn't a length. Cheers, -- tlvp

Reply to
tlvp

You need a cataly$t, and a good front end man. Bring your vehicle to the front end man, lubricate him with your cataly$t ($100 should do nicely), and he'll perform the conversion for you, even adjusting things to the result you would desire (key word or phrase: "wheel alignment").

HTH. Cheers, -- tlvp

Reply to
tlvp

Depends on type of suspension. Live axle will not change. Control blade has miniscule toe change under power.

Reply to
pedro1492

I agree that I'm confused (which is why I am hesitating to respond because I don't wish to muddy the technical issue further for everyone).

The problem with doing camber at home is different from the problem of doing toe at home.

For my bimmer, the camber is specified in degrees, and the measurement tools we're exploring measure in degrees.

We just have to solve the conceptually simple problem of a. Accuracy to 1 minute of angular measurement b. Creating a wheel plate that meets that accuracy c. Measuring to that accuracy with a mobile device

The problem, for my bimmer, is that the manufacturer specifies the toe in degrees, yet we measure in inches. The conversion confuses me to no end (which is obvious to all).

However, that specific translation problem may be solved if I trust this layman's chart, for a similar vehicle:

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Which puts the toe-in in inch measurements of: Front toe (left): Minimum = 1/32", Maximum = 3/32" Front toe (right): Minimum = 1/32", Maximum = 3/32" Front toe (total): Minimum = 1/32", Maximum = 3/16"

As with all specs written by laypeople, I can't tell if that toe is to the centerline of the bimmer or wheel to wheel but since they specify a single-wheel toe, can I safely presume that the spec is to the *centerline* of the vehicle?

Reply to
John Harmon

Anyone can catalyze a reaction, but the catalyst remains unchanged.

That is, if I do that, I learn absolutely nothing.

I remain as uneducated as before.

Reply to
John Harmon

Just Repeating so you don't miss my post. I would like to know if my explanation made any sense to you. Be sure to use the trig calculator to help you understand. Maybe even draw out a few right triangles get the idea

Reply to
amdx

What we don't want is advice from people who would never contemplate doing a camber measurement at home.

We want advice from people who have actually checked camber at home:

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All the advice from tlvp, for example, of why he would NOT to check his camber at home is and was already known before he posted anything. He added negative value to this thread.

Since he would never do it, he has never thought about how to do it, and since he not only knows not how to do it, but more importantly, he has never done it, so his advice not to do it doesn't help anyone.

He simply wasted everyone's time with his fear-filled response.

Likewise, you waste everyone's time with your I-won't-tell-you response. If you're not going to tell anyone anything, then why bother responding?

Besides, you only pretend to have done it, which is fine, but you playing make believe doesn't help anyone here. I knew all this would happen, because most people are utterly horrified at the mere thought of checking camber at home so I was trying to avoid having to respond to comments like yours and tlvp's which simply waste everyone's time.

Based on these specs (

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the measurement range is plus or minus 3 degrees to an accuracy of plus or minus one minute.

If we can't achieve one minute of accuracy out of a mobile device, what

*is* the accuracy thqt we *can* achieve out of a mobile device?
Reply to
John Harmon

Nice graphic!

To your point, I completely agree that I'm utterly confused when it comes to "toe" angles.

It was my mistake to ever bring in the concept of "toe" to this discussion because, while measuring toe with a tape measure at home is relatively easy (once the mechanical overhang problem is solved), *converting* the damn manufacturer's spec from angles to inches is the *confusion* I have.

Here is the toe spec for a similar vehicle to mine:

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Notice that the "total toe" spec is 0 degrees 14 minutes plus or minus 10 minutes.

Also notice that the measurement accuracy for "total wheel toe" is also given in similar units of a measuring accuracy of plus or minus two minutes in a measuring range of plus or minus two degrees within a measuring range of plus or minus 18 degrees.

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I admit I'm confused. My dilemma is understanding how to *measure* to that spec.

Reply to
John Harmon

Except that the manufacture specifies toe in angles but I would measure toe in distance.

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Hence it's obvious to all that I am confused how to do that.

Reply to
John Harmon

This off-topic confusion is all my fault.

I should never have brought toe into this discussion because toe is easily done at home when you have specs that are in linear dimensions such as inches but not so easily understood when you have toe specs in angles.

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Clearly I'm confused how to do the conversion.

Reply to
John Harmon

But angles are the units that the manufacturer provides for toe while I'm almost certainly going to measure toe with a distance measurement.

The manufacturer specifies the "total toe" as 0 degrees 14 minutes plus or minus 10 minutes:

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The manufacturer specifies a "total toe" required accuracy of plus or minus

2 minutes in a measuring range of plus or minus two degrees with a total measuring range of plus or minus 18 degrees.
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So this confusion is all my fault.

Clearly I'm confused because the way I think of toe is linear, but the manufacturer specifies toe in angles, so I should not have brought up toe in the first place.

Camber is simpler because the manufacturer specifies angles and the measurement is in angles.

So we should stick with camber for this thread (because it's a simpler problem).

Reply to
John Harmon

No you can not. Total toe iis the difference between the track at the front of the tire and the track at the rear of the tire. devided by 2. The specification on the Bimmer and most cars today is given as the toe PER SIDE, which theoretically is 1/2 of the total toe.. The toe per wheel is measured to the parallel longitudinal axis of the vehicle and is given per wheel to enable centering of the steering linkage so the car goes straight when the wheel is centered.

The reason the measurements are given as an angle is because that is essentially what you are setting. You are setting the angular relationship between the wheel and the longitudinal axis of the car. A linear measurement is not an accurate specification because differen diameter wheels can be used on vehicles, and the displacement of the neasurement from the rolling axis of the tire affects the linear measurement, but not the angular measurement. If you are not using professional equipment and you are depending on calculated linear measurements the ONLY way to aproach the accuracy BMW is specifying is by extending the measurement to at least 3 feet, prefferably 6 to 10, and calculatinf the offset at that point.

But I'm wasting my breath - You've been told this several times and it has not gortten through to you. Stop being a cheap-assed wannabee, find a good mechanic - and TRUST HIM. Pay him what the job is worth. If you can't afford to proain a bimmer, drive a bloody Chevy!!

Reply to
clare

You can educate youself on what an alignment consists of, and understand what is involved, without doing it yourself. I think your problem is you have a fear of mechanics - an ingrained mistrust - combined with a very tight grip on your money (although how that goes along with driving a wiener wagon, I cannot for the life of me figure out)

Reply to
clare

not if you want to do it correctly, you won't.

Reply to
nospam

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