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Old 09-09-2012, 10:49 PM
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bluebee bluebee is offline
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Location: San Jose, California
 
Join Date: Mar 2008
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Mein Auto: 02 BMW 525i M54 auto 130K
Quote:
Originally Posted by Flybot View Post
I cant tell exactly what your method will be without the pics
Here's a pic of the simple $7 toe measurement tool so far:
a) At least 5 feet of EMT tubing ($2)
b) EMT clamps ($50 each, you only need two but I have four mounted so I could reference the centerline if found)
c) Two foot 5/8x18 threaded rod ($2) & nuts ($1)


What I'm missing is a 'pointer' at the top of the threaded rod to hit the centerline tread mark.

Any ideas for that pointer?

Note: I'm thinking of cutting a notch in the threaded rod but, for ease of measurement, I prefer a solid metal block that is the same size as the clamp so that I can simply measure from the edge of one clamp to the edge of another clamp instead of inferring the distance to the centerline of the clamp (where the threaded rod is mounted).

Do you know where I can buy a solid block of metal? Lowe's didn't have any.


Quote:
Originally Posted by Flybot View Post
I highly suggest ... taking measurements from the metal rim and not the tire
The measurement location for toe has always confused me.

First, it seems we should measure to the known centerline of the vehicle (instead of to the other wheel/tire on the axle).
To that end, I ask:
Q: Do we have a good easy-to-mark centerline point for the E39?
Note: The extra clamps in the middle of the tool are there to take advantage, somehow, of the centerline mark.

Secondly, it confuses me where to measure on the wheel/tire because the distance from one wheel to another measured at the furthest point forward on the horizontal centerline will be different than the distance measured from the rim (which is a few inches closer to the vertical centerline of the wheel where the toe is, by definition, 0 ... because it's the non-changing pivot point on the ground).

Most DIYs I've seen suggest the 3 o'clock & 9 o'clock position of the tire for front-to-back toe ... but that could change depending on the size of the tires (i.e., depending on the distance between the outside metal rim and the outside rubber tread).

So I'm confused as to the best location to measure toe from.

BTW, do we know the "official" 0 toe distance between wheels on the front and rear axle?

I roughly measured mine at about 59 5/8 inches today from the front of the tire on the ground; but that isn't where the official spec is measured and it doesn't take into account any existing toe.

In summary, these are the questions:
Q1: Do we have an easy-to-use centerline mark on the underside of the E39?

Q2: What is the official distance between the wheels when there is 0 toe?

Q3: Since the toe specification is from the outside tread, how does that take into account the tire size (and would it work to measure from the rim without changing the specification)?
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Each repair should invariably add to our knowledge base by the process of inexorable incrementalism.
Your job, in return, is to read the suggested threads, where the best people will always add value to those threads, either by pictures or by descriptions, so the next person with the same problem stands on your shoulders.
See also: E39 Bestlinks & How to easily find what you need

Last edited by bluebee; 09-09-2012 at 11:14 PM.
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