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7/16 wheel studs for 14bolt SF?

ashman

ashman

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I'm putting a 14bolt SF out of a '93 into my '72 and I'm wondering if it's possible to put 7/16 wheel studs on it.

The 14 bolt axles have a .625 knurl from what I'm reading, but I can't find any 7/16 studs with a knurl that big.

I know that the "normal" thing to do would be to go bigger studs in the front, rather than smaller in the back, but my rims have a very small hole to fit the lug wrench in. My current lugs take a 3/4" wrench and I don't think I'd be able to get a bigger one in there.

Anybody got a source for 7/16" studs with a .625 knurl?
 
The lugs on my 14sf are 3/4", the lug itself isn't physically any larger than the 7/16" lug that came off. I run factory rally wheels with no issues.
 
CK10 said:
The lugs on my 14sf are 3/4", the lug itself isn't physically any larger than the 7/16" lug that came off. I run factory rally wheels with no issues.
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Interesting. After reading your post, I was able to find some lug nuts on summit that were 14mm x 1.5 (matches the current studs) that use a 3/4" wrench.
https://www.summitracing.com/parts/rnb-711-606/overview/year/1993/make/gmc/model/k1500

I'd still like to change out the studs if I can so I use all the same lug nuts, but that looks like it might work if I can't find something. I guess I could drill the holes out in the front and put bigger studs in to match too... :thinking:
 
I'll end up swapping my fronts to 14mm next time I do brakes. IMO if I have to pay to change something on my truck I'm not going to make it weaker.
 
why down grad wheel stud size ?
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I was concerned about being able to fit a larger socket into the holes in my rims. If I can find 14mm lug nuts that take the same 3/4" socket/wrench then I guess that isn't much of a concern. That said, I've never broken a wheel stud before so I don't really have strength concerns with the 7/16" studs I have and I'd rather not replace 24+ lug nuts. Obviously that isn't a deal breaker, but I'm exploring my options.
 
From what I experienced, the design of the 14MM lug nuts is a problem with rims designed for 7/16" lug nuts. The 14MM's were not "sharp" enough to fit into the hole in the wheel, so there was minimal contact between the nut and wheel. I'm not sure if taper was different as well (I just checked, it seems 60* is the common angle on both) Just to clarify, 14MM is about .55". 7/16" is .4375". The narrowest portion of the 14MM lug nut is therefore at the least .11" bigger than the 7/16" nut.

These were with factory wheels, I let my buddy borrow the wheels for awhile, and he was the one that noticed how the holes were buggered up from the 14MM nuts.

I converted to 1/2" studs (easy on the rear, not so much on the front) to match my 14SF and 10b lug nuts, and did not have the same issue.
 
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I can't find my post, but based on how the fronts are setup with the disk, the only stud I could find that was equivalent was for a late 60's Dodge.

The knurl is not at the head of the stud stock, so it bites into the hub not the rotor.
 
What I went through when look for studs for mine was going to NAPA, they looked at the book, had a couple of options. I bought one of each, took them to try, and went back and returned the one not needed. Minimal hassle...
I believe that I have the number at home.
Then I bought new lug nuts all the way around after drilling and changing the fronts.
 
dyeager535 said:
I can't find my post, but based on how the fronts are setup with the disk, the only stud I could find that was equivalent was for a late 60's Dodge.

The knurl is not at the head of the stud stock, so it bites into the hub not the rotor.
Click to expand...

very good point on the stud gripping the hub not the rotor ! ! !
 
yeah, I saw it.

I just test fit one of the wheels on the 14bolt. It seems like everything would mount up ok. Lug nuts appear to have the same taper. :thinking:

Anyone else have the same issue?
 
As long as the taper of the lug nut mates with the lug seat of the wheel you won't have an issue. K1500s and 6lug K2500s used the same steel wheels, the 1/2ton truck had 12mm studs and the 3/4 ton had 14mm studs.
 
I've decided to go with the 1/2" stuff. I test fit some some of the ones I linked above and I think it's going to work out pretty well.
 
ashman said:
I've decided to go with the 1/2" stuff. I test fit some some of the ones I linked above and I think it's going to work out pretty well.
Click to expand...

Only issue to be aware of is that those front studs (they appear to be what I used, which I can't find the PN for) are likely going to be shorter when installed than you will expect.

The general rule of fasteners that I have heard/read is that the amount of nut thread engagement needs to be the same as the diameter of the bolt/stud. I did the measurements, on my stock wheels the lug nuts/studs met that criteria, but it was pretty close. On open-ended lug nuts, the threads do not protrude at all. Which looks somewhat scary, but has not loosened up on me.
 
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