The physics of wheel studs - please educate me (1 Viewer)

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In general, shear is not carried through threaded features as a structural load path. There are too many tolerances that come into play to make to make that path reliable. The shear capacity of threaded features is much lower, with higher stress concentrations in the root of the thread. Then there is diametric tolerance on the holes in the wheel and on the threaded studs, combined with positional tolerance of the holes and studs. When looking at the stack up, especially when considering mass-production methods and manufacturer variances once non-OE parts are introduced, there would be no way to evenly distribute a shear load through the studs. More than likely one stud would have to take the entirety of the load, and I think intuitively we can see that one stud is not capable of that.
Exactly. People need to get away from the idea that it is either shear of the studs or even the hub centric ring keeping the wheel centered on the hub during operation.

It is 100% the friction provided by clamping force of tight lugs. The hub centric ring and lug holes simply center the wheel before tightening.
 
Great reply! I agree with all you say. I would not consider a non-hub centric spacer. The 1/2" spacers I have test fit are hub centric Bora spacers, not the Autozone, Darwin Award special. A 1" spacer with integral studs would likely fix my KDSS issue but then cause an issue on the back side. If I can find a 1" spacer to try, I could test that. I think though, the difference between two types of spacers really comes down to which set of non-ideal things relative to just having the right offset wheel you want to live with.
I believe I remember someone saying Bora would make a 3/4" spacer with integral studs. That might be a happy medium if true.
 
That is what I'm running .. bora 3/4 with studs. Now the oem studs sick out about 1/4" but they fit inside the dimples of the newer lc200 oem wheels.
Some of the older oem wheels will not work, and i forget that year is effected, in which case the stud needs to be ground down or cut off.
 
That is what I'm running .. bora 3/4 with studs. Now the oem studs sick out about 1/4" but they fit inside the dimples of the newer lc200 oem wheels.
Some of the older oem wheels will not work, and i forget that year is effected, in which case the stud needs to be ground down or cut off.
The thing about spacers w/ studs that I do not like is that with those, I have another 20 lug nuts to worry about being torqued that need the wheel removed to check/retourque. I realize that after a few hundred miles, they should not be coming loose but that is my worry. I've had one close call with a wheel becoming loose due to my stupidity and I've seen several others come off on other vehicles so I've developed a bit of OCD about torqueing lug nuts.
 
I missed this thread but the algo didnt: watched this while the discussion went on. Bolts are strong AF in tensile applications like this.

 
My understanding is that the wheel studs when tightened act as a clamping force holding the wheel to the hub. The greater your clamping force, the greater the force required for the wheel to slip on the hub due to the friction between the two. Therefore in ideal situations there will not be a bending load on the stud.

As the vehicle is in motion the stress on the stud won’t change unless the the vertical component of the force applied on the wheel becomes greater than the clamping force on the wheel. If this occurs the wheel stud can have a bending moment or shear.

By adding a wheel spacer or longer wheel studs you are changing nothing related to the physics of holding the wheel to the hub.

Failure often seems to happen due to a lack of sufficient clamping force, too much clamping force, or purchasing cheap spacers that introduce flexing into the equation.

Full Disclaimer: I am a sophomore aspiring ME major and am not a PE. These are just my thoughts. Do your own verification.
As a 15yr ME you are Correct - But Trusting Nerds is Very Dangerous!

Clamping force Maintained = All Good.
Clamping force Not Maintained = All Bad

I definitely would not Run Spacers without Checking Wheel Lug Nut Torque Often.

Think about the Weight (75#+) and the Circumference of a 35" Tire and you can see the Force Multiplication Factor.

For KISS The Torque = Force (Mass of Tire) x Lever Arm (Radius - Center of Tire to Edge of Tire). Because this is Multplying even 1" Larger Diameter means torque is Significantly Increased and the Mass Moves Further from Center of Wheel.
 
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As a 15yr ME you are Correct - But Trusting Nerds is Very Dangerous!

Clamping force Maintained = All Good.
Clamping force Not Maintained = All Bad

I definitely would not Run Spacers without Checking Wheel Lug Nut Torque Often.

Think about the Weight (75#+) and the Circumference of a 35" Tire and you can see the Force Multiplication Factor.

For KISS The Torque = Force (Mass of Tire) x Lever Arm (Circumference of Tire). Because this is Multplying even 1" Larger Diameter means torque is Significantly Increased and the Mass Moves Further from Center of Wheel.

This is a great point. Curious to your input but since going to 35s, I've increase the torque on my lugs about 10% over factory or about 110 ft-lbs. For both my spacer and wheel lugs. Figured the added preload can help against the increased loads from the larger tire.
 
The biggest issue with spacers that don’t introduce their own studs is reduced thread engagement with the lug nut. If you run quality extended studs you’ve mitigated this problem.
I'm getting back to this and will have opportunity to try my 1/2" spacers but need extended studs and I'm having a hard time finding what I think I need.

The OEM studs are p/n 90942-02083. It seems odd to me but the Toyota parts sellers and dealers that sell these don't seem to publish the specs (size, length and thread pitch) when I search the part number. I believe the specs are:

M14-1.5 with 16.5 mm knurl and 45.1 length (got that from Dorman site) and they look like this:

1697574594622.png


Not sure what the 45.1 mm length really means. It appears to be the total length of the stud not just the thread length:

1697575372322.png

So what I want is the same thing but at least 13mm longer. I can probably go somewhat longer as the acorn lug nuts are deep enough to accommodate more stud length. The pic above comes from this EBAY site but there is no knurl diameter spec though they are advertised as "Toyota Sequoia Extended" studs. I think these would physically go in but I'm not installing wheel studs unless I can absolutely know the manufacture so these aren't really an option without more info on the actual manufacture.

I found a Tundra forum post that suggested using Dorman 610-471 or 610-558 studs which look like they would probably work but I'd need new lug nuts as these are for a Dodge Ram and have SAE diameter and thread pitch (9/16-18)

All of the aftermarket sites that sell studs seem to be only searchable using MY, Make, and model. Dorman would be good but you can't just search by stud dimensions and I don't see any "Toyota" M14 extended studs made by Dorman. Same for ARP. Why isn't this easy? I hope the answer is I'm just bad at google-fu and someone here has installed extended lugs for spacers or thicker wheel flanges.
 
Why isn't this easy?

That’s the thing. In an attempt to make it easier for the average person they’ve made it harder if not impossible for the people who know what they’re doing.
 
I did this search a couple years ago and ended with these two possible stud solutions:
Two wheel studs seem available with 16.3mm knurl and long enough length to make it worth while.
Nice Products S-6330 - can't seem to find a distributor to ship to US
KYO-EI HUB BOLT M14xP1.5 SBLC - $9 each (on sale for $5 each!)
 
In Australia but you can find what you need here:

 
Dorman has the more detailed search a bit hidden under Visual Search:


Unfortunately, the only few within the range of 16.5 - 16.6 mm knurl are Toyota studs - nothing a bit longer like you're looking for.
Well, maybe I’ll try the EBay studs for prof of concept. If the 1/2” doesn’t help me clear my KDSS rub like I think it will, it doesn’t really matter. If it works I could then go with the Ram studs and get new lug nuts.
 
In Australia but you can find what you need here:

Thanks cool site. Can’t figure out how to efficiently search but theyb
In Australia but you can find what you need here:

cool site they seem to have 15mm thick spacers with integral studs. If I can find the right size, I could just do that.
 
I did this search a couple years ago and ended with these two possible stud solutions:
Two wheel studs seem available with 16.3mm knurl and long enough length to make it worth while.
Nice Products S-6330 - can't seem to find a distributor to ship to US
KYO-EI HUB BOLT M14xP1.5 SBLC - $9 each (on sale for $5 each!)

Thanks. Shipping is $85. Total with shipping came to $185 for 20 studs. Better than $5 each.
 
Ordered the cheapo EBAY 60mm studs (pack of 20) for $22 shipped just to test fitment and figure out of the 1/2" spacers will solve my rub issue or not. The manufacture/"brand" listed on the EBAY site is "v-project innovation". Anyone heard of that? I googled it and found some references and they appear to make (or at least sell) spacers and other related stuff though I don't see any 60mm studs on their direct site. I don't see me really using these other than a test fit. Maybe they are fine and spending $200 is a waste but I've seen wheels come off and it isn't anything I want to experience nor do I want to always be worried about it.
 
Did you end up installing these from Nice? How did it go?

What part number did you get?
I haven't done anything yet. The rub is somehow much less on the new 200 with my old suspension moved over and realignment though I haven't really had time to look at it in any detail. I have a lot of other things I need to sort out on the new 200 first but I'll eventually get back to the spacer thing.
 
Has anyone tried the black halk ones? It says 55mm length, not sure if this is thread or total. Can anyone confirm what the actual difference is to stock?
 

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