Overloaded wheel Breakage

[woodhog]

OUCH!

This was very interesting, now I am glad we got rid of our stock wheels.

In our case the 3500 Dodge SRW came with tires rated at about 3000 pounds each, I tried to find out what the wheel rating was, there was no stamp inside the rim, even asked the truck manufacturer, they did not provide the wheel rating either, so went with Rickson 19.5 inch, 5000 pound per wheel.

Why are they reducing the weight carrying ability of these trucks with the
low rated factory tires and wheels?

[sandblast]

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

X2

[JIMNLIN]

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

[mkirsch]

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.

[Grit_dog]

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.

[ticki2]

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 .

[jaycocreek]

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..

[ticki2]

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 .

[jimh406]

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.

[ticki2]

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 .

[jimh406]

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-wheel...

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.

[DWeikert]

jimh425 wrote:
I think the lug bolts don’t carry much if the wheels are hub centric. However, I have heard of bolts breaking if the wheels get loose.

Hub or lug centric is irrelevant regarding load. The load is carried by the friction between the wheel and mating surface. This friction is created by the clamping force of the lugs which is why proper torque on our lug nuts is important. This is also the reason you don't want any grease or oil on those mating surfaces.

"Centric" refers to how a wheel is centered while mounting. Hub centric wheels are good for manufacturing because the wheel can be mounted on the vehicle then the lug nuts just torqued down. With a lug centered wheel more care must be taken while installing and tightening the lugs.

[burningman]

Siletzspey wrote:
FYI/question - on a 1-ton, the tire, wheel, axle, spring and frame ratings tend to be max'ed out equally, so upgrading just one component doesn't necessarily buy you much. I read what seemed like a fairly competent posting elsewhere that the lug bolts (pattern, count, size) are another weight-rated link-in-the-chain to consider. While the tires always win the weakest-link award, I wonder where lug bolts fall in the line-up?

Axles are in fact very under-rated by the truck makers.
If you check with the axle makers, you’ll find that 3/4 and 1-ton rear axles are rated a whole lot higher than the truck makers claim.

Upgrading wheels and tires gets you real benefits.

[Boondocking2019]

In my search for upgrading Tires and Wheels for my F350 SRW several large tire / wheel dealers suggested the Method 305 NV Heavy Duty Wheels. I just installed these wheels and they’re listed as having the highest load rating for 18” Wheels that I can find. On the backside of the wheel it’s stamped (6 Lug 3500 lb rating) and (8 Lug 4500 lb rating). So clearly this manufacturer is labeling the weight rating for Lug Nut Application. How many wheel manufacturers stamp the Lug nut weight capacity by Lug application?
This thread has opinions on after market versus OEM wheels and my Super Duty F350 SRW is not a grocery getter it was purchased to haul a 12000 lb 5th Wheel or my new 89RBS Adventurer Camper. The F350 OEM Wheels at 3650 # rating would cover my 7000# Door Sticker for the rear axle weight, but the Campers loaded Wet weight is a little over and this prompted upgrading to the 4080# 295/70R/18 Cooper Tires and the wider 18x9 Method Wheel at 4500# Rating. Attention to monitoring Tire Pressures often and checking Wheel Torque especially the rear axle has been a Standard Operating Procedure for many years of RVing.

[covered_wagon]

Alcoa wheels are expensive and have a high rating by comparison. They need sticky weights inside the wheel because the regular weights will cause a white rash to form on the coating with the outer edge hammer on weights. You also need to scrape the mating surfaces anytime you have the wheels off because there is always a bit of scale from the corrosion being that its against a steel hub all the time. This so you can torque them to at least 120 ft lbs. Mine are not hub centric just well torqued with a good torque wrench. been hauling the camper with them for 16 yrs this October. They are the highest rated 16 inch rim you can find.

I don't want 19.5's because I think they are too hard on the running gear with 3.55 gears. Maybe alright with 4.10 running gears