Lug bolts. Really? Whose bright idea was that?

Forums: Autos, Cars, German, Conspiracy, Engineering
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Today I helped my brother change his brake pads on his late model VW Jetta.
Why on Earth does the wheel attach to the hub with lug bolts rather than using lug nuts?
So frustrating to line up the wheel to the hub in order to thread the bolts.
Engineers defend yourselves! Wink

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Type: Question • Score: 10 • Views: 7,744 • Replies: 60

View best answer, chosen by MattDavis

@MattDavis,

I'd always heard of a bolt as a screw and a nut tho for some reason I like "nuts" better

Quote:

……. in order to thread the bolts.

Matt you'll have to explain that one. If one of the screws needs threading you might be in real trouble owing to the likelihood of interference to the handle of the typical threading die holder. If you're lucky the screw can be released though typically they're part of the wheel (that is, the brake drum). So you might have to look for the holder that mounts by means of an integral shaft

If not Crystal clear Matt forgive, but it would take all day to find exactly the right terms

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@MattDavis,

You know Germans, they like to make your life difficult.
Lug nuts win on convenience, definitely. I don't think it's a strenght issue. Semi's in America use studs/nuts while trucks in Germany use bolts.
Let's leave it at that: it's a German thing.

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@Ice Demon,

How thick is the brake drum, or whatever the studs attach to? Does it have the thickness for the bolts to develope full strength? I think a bolt needs to be threaded into something with a thickness at least half the diameter of the bolts, and that means thick enough for full threads, plus the taper of the tap. Wheel studs are normally pressed in from the opposite side, and don't depend on threads.

Anyhow, do you really want to hold the weight of the tire/wheel in one hand and align the first hole while holding that weight? You will need the other hand for the first bolt, of course.

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@dalehileman,

"Standard configuration"

http://www.motorera.com/dictionary/pics/W/wheel_hub.jpg

In this setup, the wheel can be placed over the threaded pins, and lug nuts are added next to secure the wheel to the hub.

On the VW. There are no threaded pins. The holes in the hub and the holes in the wheel must be perfectly aligned, then lug bolts can be threaded into the hub.

http://www.tirerack.com/images/wheels/tech/lug_nut.jpg

The perfectly alignment part is a pain in the @$$.

Any engineering benefit to the lug bolt preference by VW, is unclear to me.
It seems like it serves only to make things more difficult.

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@roger,

Roger wrote:

Anyhow, do you really want to hold the weight of the tire/wheel in one hand and align the first hole while holding that weight? You will need the other hand for the first bolt, of course.

This is exactly the frustrating part of dealing with lug bolts.
Ficken Radbolzen!

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@Ice Demon,

Ice Demon wrote:

Let's leave it at that: it's a German thing.

This is my suspicion. I really want to hear the engineering justification for this travesty.
Warum sind Radbolzen besser als Radmuttern?

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@MattDavis,

Boy I gotta leave it to you guys, you really know your stuff Anyhow what I referred to as "screw" should be called "stud" which I assume you're referring to as "pin"

Unless of course it not part of the hub flange in which case ok also to call "screw"

Edited to note however that apparently the illustration is everything except VW. If I understand your OP correctly, then, the latter's wheel has threaded holes in the flange, then I can indeed sympathize how difficult lining up the wheel

Sometimes Matt I deplore my German ancestry

1 Reply

@roger,

I don't remember any specification. Somehow it came into a conversation while discussing Top Gear with a trucker in a restaurant during my trip there. It's one of those of miscellaneous information you scoop along life. He didn't seem to mind and talked about how it's cheaper in general.
Just think how much harder it'll be to install a wheel on the side of the road without having an extra pair of two hands to hold the wheel aligned in place while inserting the bolts, especially with tires on the scale of semi truck proportions?

1 Reply

@MattDavis,

You ever think that German engineers are so posh that they've never had to change a tire in their lives?

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@Ice Demon,

Ice it's like computer programmers, especially those assigned to write text editing routines. If everything is made as difficult as possible, they reason, you will so much more appreciate it

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@MattDavis,

I'm thinkin' it's this. It's considerably more subtle than annexing territory.

They getcha with the lug bolts first. Where's me tinfoil hat?!?!??!

1 Reply

How the hell are national chain auto shops supposed to make a big profit if you can easily do the work yourself . . . huh . . . huh ? ! ? ! ? Sheesh . . .

1 Reply

@dalehileman,

Dale Hileman wrote:

Sometimes Matt I deplore my German ancestry.

I accept your apology. Wink

I also have a mostly German ancestry.
Now fix the problem!

1 Reply

@Ice Demon,

Ice Demon wrote:

You ever think that German engineers are so posh that they've never had to change a tire in their lives?

I suspect that many car engineers focus on the forest and neglect the trees (metaphorically of course).

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@jespah,

Jespah wrote:

It's considerably more subtle than annexing territory.
They getcha with the lug bolts first

More subtle, and yet pernicious. They are annexing the territory of the engineering mental space. Mind control as I quite obviously see it. Starts with the bolts, ends with 1984.

Jespah wrote:

Where's me tinfoil hat?!?!??!

I don't know? You can't have mine. I still need it.

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@Setanta,

Setanta wrote:

How the hell are national chain auto shops supposed to make a big profit if you can easily do the work yourself . . . huh . . . huh ? ! ? ! ? Sheesh . . .

The true cost of exclusivity. Even when I changed the fuel injector O-rings on my girlfriend's Toyota highlander, each one cost $10 (For a piece of rubber that takes less than 10 cents to make).
Dealerships... can't live with 'em... can't break into their warehouses to steal their parts. Embarrassed

1 Reply

@MattDavis,

You know Matt, I completely misread the problem. I thought you were questioning the wisdom of lug nuts instead of the other way around.

1 Reply

@Ice Demon,

Especially if you are in the Mojave desert in the middle of the night and truckers are whizzing roaring by as fast as they can.
Hmmm. That was my friend's old even back then Porsche.

1 Reply

@roger,

Roger wrote:

I thought you were questioning the wisdom of lug nuts instead of the other way around.

How dare you!
Assume I would endorse lug nuts?
What's next?
Do you assume I endorse fascism as well?!
The gall!!!

2 Replies

Lug bolts. Really? Whose bright idea was that?

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