2015 3500 wheelbstuds sheared off

[GMconvert]

I can tell you that it was not loose lug nuts!

Because if you had had loose lug nuts, you would have elongated the bolt holes in the wheels enough to be well noticeable before they left the truck. I know because I purposely loosened my lug nuts just a little bit and drove only one mile slowly from my shop in an attempt to break the rust-frozen wheels to the hub. I finally succeeded in breaking the wheels loose but in doing so, actually slotted those bolt hole ever so slightly. Kinda surprised me.

Ralph

I never said loose, I said not enough clamping force.....there is a difference... earlier in the thread there is a clear example of loose lug nuts....

 

[TCDiesel]

The Ram Hub Pilot is system is NOT forgiving, Your Stud/Nut should be virgins. Now here's the big problem The clamping force must be tits on, Your Nut is surface force, No washer between surface and NUT, this makes it extremely difficult for correct clamping...Example the force is NOT on the surface of Nut and rim matting surfaces, your force is threads of stud and nut, its only time before the clamping force of NUT/STUD threads fail, conditions like speed,GVW,Road all will effect how long before it fails. If you are is annul as I am On hub systems all the matting surfaces must be clean and polish, I also check the Stud nut treads for correct machining matting surface 000.2+- if the stud nuts don't meet the test I return them. https://www.arconic.com/global/en/products/info_page.asp?info_page_id=527&prod_id=1274#

 

[Wayne M.]

TC, you make this sound like a pattern failure. This is not something heard/ seen everyday. How much different is the Ram system from Ford or GM? I know Ford uses a flanged/floating nut, that makes a huge difference?

 

[truckmen]

I never said loose, I said not enough clamping force.....there is a difference... earlier in the thread there is a clear example of loose lug nuts....

Ooops, sorry, I stand corrected.

 

[TCDiesel]

TC, you make this sound like a pattern failure. This is not something heard/ seen everyday. How much different is the Ram system from Ford or GM? I know Ford uses a flanged/floating nut, that makes a huge difference?

Its the same...Think like this if a washer wash placed between nut and rim, the washer would spin tightening on the threads.Thus Your Force is on the threads. When you tighten down without the washer Your clamping force is divided between the threads and the mating surface, the force must be equal. lets say 150FT TQ more force on threads than mating surface, remember the nut is spinning and the stud is stationary, when the flange of the nut meet the rim force is needed that's produce by the threads, which is greater the force on the threads or mating surface... YOU hope threads BC if the mating surface is greater the threads will allow movement. shearing the stud.

 

[GMconvert]

Its the same...Think like this if a washer wash placed between nut and rim, the washer would spin tightening on the threads.Thus Your Force is on the threads. When you tighten down without the washer Your clamping force is divided between the threads and the mating surface, the force must be equal. lets say 150FT TQ more force on threads than mating surface, remember the nut is spinning and the stud is stationary, when the flange of the nut meet the rim force is needed that's produce by the threads, which is greater the force on the threads or mating surface... YOU hope threads BC if the mating surface is greater the threads will allow movement. shearing the stud.

The OPs stud pictures don't show a shear failure....it is a tensile failure!

 

[GMconvert]

In the attached photo, the red arrows indicate the crack initiation sites (multiple, all the way around it)....the blue arrows show beach marks (direction of crack growth)....the yellow arrows look like areas of final separation. The failure mode looks to be cyclical tensile with some associated bending, no shear. There is a feature in the photo that would be considered a shear lip (the top yellow arrow), but it is not the result of the stud being in shear, it is a result of final separation. Tensile test samples get shear lips around the outer periphery during testing. From the looks of it, that stud was at least 75% cracked through the cross section before final separation.

 

[TCDiesel]

I was just using the term (Sheared) broadly.

 

[Wayne M.]

I'd like to know how Ky is doing with this, and what his shop wound up doing.
If I were his shop, I'd measure and inspect the hub for straightness, concentricity, radial runout and the condition of the stud bores. Then I'd get a set of OEM fasteners to install properly, along with a full set of proper fitting hub piloted wheels. I'd install them and HAND torque the nuts properly. Then I'd have him return as frequent as possible (daily?) for a tightness check and inspection. I would expect the fasteners to be snugged up a couple of times, but settle after a few heavy hauls.
I think it's quite possible that the limits of these hubs may be exceeded if the fasteners don't settle down.

 

[run2trouble]

I meant to get a better picture off the first set of studs failing when I was home and got busy doing other stuff. I’ll get them when I head back for Christmas.

I ended up getting a set of wheels sent home that are hub centric, and got them installed.

I retorqued every 50-75 miles for 300 miles or so all the way home from Oregon. After the new wheels were installed I checked them every 50-75 miles and they seemed to settle in after about 150 miles. I’ve made it a point to check them every day when I do my pretrip inspection and they seem to have seated correctly.

I do appreciate the info and feedback from the TDR members.

 

[GMconvert]

I am still interested to see photos of the failed studs from the first time. It would also be interesting to see the 19.5 wheels you have, especially the bolt hole and center bore area.

I have Rickson 19.5" wheels on my SRW 3500, they are thick! If you read the SAE wheel testing spec, you get the clear picture they are concerned with wheel stiffness, not wether it is hub centric or stud centric! And the acceptance criteria to the spec is not having more than 1 stud break at Max load for over a million cycles.

 

[GMconvert]

What people need to remember is the wheel is trying to deform on the lower half every time it goes around. If you mark a spot on the wheel and think of how that behaves every rotation, it goes from loaded to unloaded. Even though you don't see deformation every rotation, that is what the stresses are trying to do to the wheel.

Another thing think about is a bicycle wheel....how do you think the spokes work? They work opposite of a solid wheel....the hub hangs from the upper spokes...the lower spokes are not supporting the load....so a spoke gets loaded and unloaded every rotation.

 

[Wayne M.]

I meant to get a better picture off the first set of studs failing when I was home and got busy doing other stuff. I’ll get them when I head back for Christmas.

I ended up getting a set of wheels sent home that are hub centric, and got them installed.

I retorqued every 50-75 miles for 300 miles or so all the way home from Oregon. After the new wheels were installed I checked them every 50-75 miles and they seemed to settle in after about 150 miles. I’ve made it a point to check them every day when I do my pretrip inspection and they seem to have seated correctly.

I do appreciate the info and feedback from the TDR members.

Glad to hear! Wheel nut torque and settling is so important.

 

[stickk]

2017 3500 DRW passenger side with 5700 miles. Just 1 lug/nut left when I noticed the center cap missing. Luckily I was 1 mile from a dealer.

 

[stickk]

Dealer had never seen this before, at least the current service manager. They fixed under warranty. His thought was that the dealer I bought it from didn't check the lugs for proper torque before delivery. There were stud thread marks front and back of wheel lug hole indicating that the wheel was moving back and forth under acceleration and braking.

 

[Wayne M.]

stickk, what's your loads like? Do you tow heavy? Have you ever retorqued them yourself?

 

[stickk]

At that time I had only 5700 miles on the truck. I had towed my fifth wheel once for 200 miles, never had the tires rotated at that time or checked torque on lug nuts. I'm 45, have put well over 500k miles on my trucks and have never checked lug nuts. I do check my trailers though. This is my first dually.

 

[stickk]

I meant to upload this pic earlier

 

[Wayne M.]

Have any other shots of that hub?

 

[GMconvert]

View attachment 100887 I meant to upload this pic earlier

Can't tell much from that photo....rather blurry once it is enlarged.