Overloaded wheel Breakage

SidecarFlip wrote:
Give me forged Alcoa's any day.

X2

mkirsch wrote:
I thought wheels *NEVER* broke. That's been a staple of the "put E-rated LT tires on your 1/2 ton truck's stock rims and pump them up to 80PSI" argument for as long as I've been a member of this site.

:B

I thought wheels *NEVER* broke. That's been a staple of the "put E-rated LT tires on your 1/2 ton truck's stock rims and pump them up to 80PSI" argument for as long as I've been a member of this site.

All, unless you’re going to go through all the calcs to determine the failure mode or weak link of a particular hub/wheel arrangement, you will actually never know and the vast majority of what’s been posted in the last page of this thread is supposition.
Double shear, bending, clamping force, tensile strength, even the angle of the acorn nuts all factor in to the strength of the system. And depending on the real world conditions, the max stress applied may result in a different failure mode than what one would think typical.
If y’all want to simplify it rather than try to back into the engineering reasons, then if you accept the “rating” of the highest rated truck that has the same components (In this case, wheel lugs), you can be comfortable knowing that the same components will hold up the same even in your lesser “rated” application.
Think about it this way. Hub centric/lug centric has little to do with the strength of the connection. Shear on lug studs is north of 30klbs. Tensile strength even higher.
Bending is the weakest mode of failure, that’s why ya keep yer nutz tight!
Bottom line, you’ll break something else before lugs overloading a pickup truck if the wheels have a proper connection to the hub, regardless of lug or hub centric.

Yes I have found some references for Ford wheels in Ford literature . Nothing for GM or Dodge . There is some info for Accuride wheels on there site .

ticki2 wrote:
I had an oem rear steel duel break around the bolts like that . Truck was not overloaded . Sometimes stuff just happens , possibly an original defect that took time to show up . Usually you can assume an oem steel wheel is rated at least as much as an original tire the manufacturer puts on it . Finding the actual rating of an oem wheel is near impossible .

I found my OEM wheel ratings on the factory window sticker that I finally found and downloaded..I don't know if that rating is still put on new vehicles or not but they were in '94..

Sorry , I no longer have those references handy , it was over 10 years ago when I looked into the subject . I am sure they are still out there if someone cares to research them . Just some quick thoughts . Assuming the lug nuts are tighten enough to prevent the wheel from moving , at no point is the lug bolt in contact with th wheel holes . Egging of the holes only occurs when the lugs are loose .

ticki2 wrote:
Hub centric wheels are more for convenience than load bearing

Other than your thoughts which might be right, btw. Do you have any references other than wheel manufacturers? I can find a lot of references that say that they are load bearing which is not to say the bear all of the load all of the time. See the post above yours for two.

Here’s the credentials from the writer of the bottom one

Charles C. Roberts, Jr., Ph.D., P.E., is an engineering consultant in the areas of accident reconstruction, failure analysis, structural analysis, heat transfer, fire origin analysis, computer analysis, mechanics, and biomechanics.

Hub centric wheels are more for convenience than load bearing , it helps center the wheel before final torqing the lug nuts . If it were for weight bearing it would have to be machined to much tighter tolerance and pressed fit .Almost all oem wheels now are hub centric for this reason , even on small cars . With lug centric wheels more care has to be taken to gradually tighten the cone lug nuts to insure they are all centered in the holes before final torque . Almost no aftermarket wheels are hub centric , including 19.5" , yet some have higher load ratings than oem wheels . 1ton and above dual wheel lug nuts have washers instead of cone shape to exert even more clamping force . It is also way they should be hub centric or have centering rings .

DWeikert wrote:
Hub or lug centric is irrelevant regarding load. The load is carried by the friction between the wheel and mating surface.

Read more below.

https://www.quadratec.com/c/blog/difference-between-hub-centric-and-lug-centric-wheels

Basically, hub centric means the space inside the wheel’s center bore is designed to fit perfectly on the axle. This way, the wheel is centered by the hub connection and the lugs can hold it flush against the mounting plate. In a hub-centric design, this connection will bear the weight of the Jeep.

https://www.machinedesign.com/fasteners/what-s-difference-between-lug-centric-and-hub-centric-wheels

A problem arises when using a lug-centric wheel on a vehicle and suspension that was originally a hub-centric design. Without the hub’s support, road impacts can deform lugs enough to where the wheel is no longer concentric with the hub, leading to vibrations. This can reduce the clamping force of the wheel to the hub. Road loading conditions can then move the wheel around on the hub, as can be seen by the worn holes in the image below of a lug-centric wheel used on a hub-centric vehicle.