Found spacers I didn't know I had (1 Viewer)

[Ali FJ80]

@Ali FJ80 I appreciate it. Thank you.

No problem and seems the lugs you linked above with the thread extension past the seat point would take care of this.

 

[bloc]

I'm no engineer but when I see this type of engagement on a wheel stud, it's a bit scary. I don't want to over-react but good practice suggests a nut with half the threads not engaged can be a liability. My local Discount Tire would not remount these wheels if they saw this engagement with standard conical wheel nuts.

You can see here with a standard conical wheel nut, I have about the same thread engagement at the wheel as when the spacer was installed.

I'd feel different if the world of nuts and bolts suggested a safe practice is to have 1/2 a nut's worth of threads not engaged.

View attachment 3449457

I see your point but what if a nut was 2” long yet still open on the end? Then it could very well be far less than half and still ok.

The important detail is whether there are enough threads to safely hold the wheel. The company that makes the lug nuts used on the super-popular rock warrior wheel, sold by Toyota, apparently says 5-6 is ok.

But do what makes you feel comfortable. I just like having all the information we can get from experts available to someone that may come along and read this in the future.

 

[NikP]

We can all speculate whether 5 or 6 threads of engagement is enough, that's a personal dicision. I'm simply spending $60 to buy extended lug nuts and have piece of mind. I encourage others to consider the same when they swap wheels and encounter a similar condition.

I was alarmed when I found spacers with little engagement and my concern carried over after I saw the same issue exists with a standard conical lug nut on the after-market rim.

As for the science there's an entire study out there considering sheer strengths, tensile strengths, the impact of bolt materials being stronger than the nut material and the converse, the impact of the chamfered stud and its lesser thread contact on the first 1.5-2 threads, the relationship of torque and strip-out force on threaded joints, etc... An Air Force study suggested there are 70+ variables which make up the torque coefficient calculation when applied to a threaded joint. (Trust me... all the science doesn't support 5-6 threads as being sufficient). And the science recommends the standard depth of a nut so they're all not 2 inches deep and just deep enough to engage 5-6 threads.

For the engineers out there, much of this can be found in the book : "An Introduction to the Design & Behavior of Bolted Joints". Enjoy the read.

 

[bloc]

We can all speculate whether 5 or 6 threads of engagement is enough, that's a personal dicision. I'm simply spending $60 to buy extended lug nuts and have piece of mind. I encourage others to consider the same when they swap wheels and encounter a similar condition.

I was alarmed when I found spacers with little engagement and my concern carried over after I saw the same issue exists with a standard conical lug nut on the after-market rim.

As for the science there's an entire study out there considering sheer strengths, tensile strengths, the impact of bolt materials being stronger than the nut material and the converse, the impact of the chamfered stud and its lesser thread contact on the first 1.5-2 threads, the relationship of torque and strip-out force on threaded joints, etc... An Air Force study suggested there are 70+ variables which make up the torque coefficient calculation when applied to a threaded joint. (Trust me... all the science doesn't support 5-6 threads as being sufficient). And the science recommends the standard depth of a nut so they're all not 2 inches deep and just deep enough to engage 5-6 threads.

For the engineers out there, much of this can be found in the book : "An Introduction to the Design & Behavior of Bolted Joints". Enjoy the read.

Someone should tell McGard that they are in for a lot of liability then.

 

[kcjaz]

Look what I just found on my new to me 2015:

I didn’t look closely at the wheels when I bought it as I’m ditching them (though they are nice 18” Rock Stars). I saw this thread and looked. Only 3 threads of engagement. Yikes! I can’t believe a shop would do this. I haven’t pulled off the wheel to look at the actual spacer but it feels like it’s 1 1/2 or more thick and appears to be the kind w/o it’s own studs and is just using the wheel studs. Of course to do that, they would have had to replace the OEM studs with longer ones, and if they did that, why only 3 threads?

Edit: pulled a wheel and no spacer. The flange on these Rock Star wheels is just extra think, like 1/2” or maybe double my ICONS. I had a wheel off my other 200 and counted the treads engaged with the ICONS and got 7.5 or so.

 

[NikP]

@kcjaz wow! That scares me! I thought mine were sketchy...

I ended up installing these. I now feel very comfortable with12-14 threads engaged.

Amazon product ASIN B08L75GQS3

Someone should tell McGard that they are in for a lot of liability then.

Their literature states this for lug nuts: "6. Minimum thread engagement must be equal to the thread diameter of the wheel stud." The same literature states 5.5 turns if installing their lug bolt.

At 1.5mm per revolution, minimum thread engagement is 9.3 turns.

 

[bloc]

Their literature states this for lug nuts: "6. Minimum thread engagement must be equal to the thread diameter of the wheel stud." The same literature states 5.5 turns if installing their lug bolt.

At 1.5mm per revolution, minimum thread engagement is 9.3 turns.

Thanks for posting actual literature from them…