Tonnie

It would probably be impractical to redrill and retap for larger studs, but maybe you could look for stronger stud material.

Send a picture of broken studs it could help to find the best solution.

It could be possible that you do not tighten them correctly or that the nut gets loose.

The more informations you send the better will be the answer.

This usually happens because lugs are loosening up...or studs were not fully seated...

This can also happen because we now have two different stud types in the US. Are you running stock factory wheels?

What is your application? Street, off road? Are you torquing to manufacture specs? Are you running stock wheels or offsets? Are you using a thread lock? Are you going back after a few KM's and checking torque?

The tapered end goes on first!

Make certain that you are using lugnuts compatable with the wheel (rim). If the wheel is not factory original, it may require a special taper on the shoulder of the lug nut. There are many different styles. I've seen this with after market wheels using oem lug nuts. Good luck

Have the original wheels been changed to an aftermarket wheel?

Why do i ask?

Maybe the hole centres are close but not right.

Maybe the nut seat does not match the wheel hole seat.

Are you in fact talking about the studs that hold the wheel on, or, the studs that hold the axle into the hub?

A picture speaks a thousand words.

Use windows picture viewer and resize your picture to a smaller size to suit a web page.

As already suggested by the esteemed panel and, are you overloading the truck by any chance?

Is that 500km on smooth roads or thundering through rough terrain?

Hard suspension, tyre over inflation, crappy replacement studs...

i'm not sure if you mean the bolts that mate the axle to the hub or the lug nut studs. does the truck have posi-traction? is the truck a 350 model or above? are you running factory wheels? i need more information.

When did this failure start? What changes were performed prior to the failures? Do a root cause analysis to try to come up with a possible cause. I have had many bolt failures due to improper heat treating so when replacing ask for a mechanical certificate on the studs. Not always possible but worth the effort. Lets see some photos for more informed diagnosis.

Avoid potholes........especialy the ones bigger than your truck

This will be happening because the PCD of the wheel does not match the PCD of the hub.

Somehow you've got wheels which do not match the hubs. Introduces moments to the studs, and high speed flexing does the rest.

I had the identical problem, years ago, when installing, by mistake wheels from an earlier model vehicle, and didn't know the manufacturer changed the PCD on the later.

Lucky to be here really. The vehicle shed the wheel at just under 100mph. Studs sheered clean off.

Cheers,

Stu.

As in, say, 100mm ≈ 4", but 100mm ≠ 4" exactly?

Yes, that's the kind of thing.

In my case we had metricated hubs and imperial wheels.

Nominally 4x100, but actually 4x4".

Hope this helps.

Cheers,

Stu.

You might just have hit the proverbial "Nail on the Head" with your comment.......

4" is actually 101.6mm, that is QUITE a difference!!!

Tonnie, where are you?

That should read Anthonyqmy where are you?

Some feedback would be good.

What did you eventually find?

Stu.