Wheel Stud 1/2” vs. 5/8” Bore

[Ol'Blue]

Wheels are drilled for 5/8 studs and I have stock 1/2 studs. Okay to run these with conical lug nuts?

 

[Broncobowsher]

If the taper bottoms out on the hub, it is bad. The lugnuts will be tight, but not proper clamping load on the rim. Typically an issue on steel wheels and not so on aluminum.
Then I start looking at the contact patch between the lug and the wheel. I have seen some lugnuts that have a huge tapered seat. Some are nearly nothing. A small hex lugnut that has just a chamfer (not a bulge at the seat) would get sketchy real fast.

So, maybe. Could be a total disaster, or completely safe.

 

[Yeller]

Picture of the wheel in question? With details of the hole and lug nut seat?

 

[Ol'Blue]

So if I get lug nuts that match the taper of the rim and dont bottom out I should be okay? Rims are raceline aluminum.

 

[Yeller]

That helps. Get some bulge head lug nuts and you should be fine. Something similar to These. I have some wheels drilled for 5/8 studs that I use them with. They are with 9/16 studs but the same 3/4 hex drive and OD.

 

[Ol'Blue]

Thanks Yeller!

Anyone out there change out studs to 5/8”?

 

[toddz69]

Thanks Yeller!

Anyone out there change out studs to 5/8”?

I don't know many EB owners that have - I'm guessing @68ford has. They're pretty common on full-size Bronco prerunners.

Todd Z.

 

[Yeller]

I’ve done it, but everything gets weird and you are dedicated to them from then on. I always go to 9/16” and been fine in all but the most abusive applications. Most wheels will still fit and the strength improvement is substantial. I’ve been around too many sheared 1/2” studs, only 9/16” I’ve seen sheared I don’t think 5/8” would have made the difference something was bound to let go. 9/16” stuff is standard and available most everywhere, where as 5/8 is not.

 

[Broncobowsher]

Pretty sure that my '77 F250 had factory 9/16 studs. There is a huge selection of studs. I know because I had to go through diminsions since what I had didn't match what the books said I should have. Had to match knurl, length, thread... You might find a set of 9/16 that are straight press in.

 

[Yeller]

I haven’t checked factory EB front hubs wheel studs. I can say that 78 on the wheel studs interchange between F150 and F250, F250 being 9/16. The rear axles are easy to drill out if a direct cross over isn’t realistic. Here’s A great resource, just a lot to sift through. Find what you have, note the dimensions and then start comparing in 9/16”

 

[ntsqd]

In my experience all OEM 8 lug studs from early to mid 70's and up are 9/16" up until the metric studs came along. Means that there's a huge variety of studs available. As Broncobowser and Yeller both mentioned, finding the right one can take a little time because that are so many options.

 

[Speedrdr]

I haven’t checked factory EB front hubs wheel studs. I can say that 78 on the wheel studs interchange between F150 and F250, F250 being 9/16. The rear axles are easy to drill out if a direct cross over isn’t realistic. Here’s A great resource, just a lot to sift through. Find what you have, note the dimensions and then start comparing in 9/16”

That’s a heap of wheel studs and lug nuts to look at! Bookmarked that post, you know, just in case.

 

[Yeller]

It’s worth checking 14mm too still a good upgraded and opens a few more options. .551” for 14mm and .5625 for 9/16.