Can we talk about "center bore" for a minute?

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69_340_GTS said:
114.5mm vs 4.50" is only a difference of .008". That's why it works.
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Thanks, professor! :D
Was anyone confused as to why it "works"?
Yep. It's close enough that you could probably get away with it 992/1000 times. I guess my point is that if you're working on the assumption that tolerances are imprecise enough to pull this off, the argument for a hub-centering ring is probably a bit stronger.
 
that's 1/125th of an inch

your balance is probably off more than the vibration that would cause if all five lugs were pulled to the same side by that much.

your tread is probably worn more unevenly.
 
Got a Toyota we have been driving for years with inch sized aluminum wheels that I drilled out the lug bolt holes to fit the metric lugs. Drives just fine. As mentioned above, manufacturing tolerances probably aren’t that close
 
69_340_GTS said:
Well, one would hope that the bolt holes and center hole were produced to some kind of tight tolerance during manufacturing, on both the axles and on the wheels. Actually, I've seen how modern aluminum wheels are machined. The lathe that turns them has the lug hole drilling tool in it. While the wheel is still chucked in the turning jaws/fixture, the lug holes are put in. True-position of those lug holes is probably so close you don't even need to bother measuring it. You have probably a dozen or so things that will add up to a huge tolerance stack if you want to start worrying about them. Like, what's the runout of those wheel bearings? Or the tire runout or roundness?
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Hub and wheel true position probably within .005 of an inch. Puts concentricity within .0025 of an inch. No way you are getting that close with 10 holes. But as I said, by the time you mount your tire it is all good.
 
If you are using your lug nuts to center your rims and experience a vibration that sometimes goes away when you remove and reinstall your wheel, you may want to buy hub-centric rings to center your wheel. They come in plastic or aluminum and they just cost under $5 for (4). I use them where needed regardless, best of both worlds!

Other than that, if it is working for you, leave it alone.

Problems come from wheels being over torqued, one lug being driven home before the others, the conical seat in your soft aluminum rims being torn up, conical lug nuts being gouged and wrecking the seat in the rim further...
 
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MRGTX said:
Good points.
However, I think we could make a case that modern Ford wheels are closer to classic Mopar wheels than modern Mopar wheels are. At least the Ford wheels have the 5x4.5 bolt pattern. :)

Speaking of hubcentric wheels, I know some guys get away with running modern 5x114.5 Charger/Challenger wheels because they're "close enough." This is where tolerances might start to stack up in a bad way.
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Oddly enough, the 17" Charger steelies we have been running for several years now are absolutely hubcentric on our 73 dart. Amazing that hub diameter is the same from 73 to 07
 
There was a great example of over analysis by an "engineer" over on the B body side-

An engineer (he took the opportunity to mention that several times in his posts), over in England, bought a 73/74 Charger and couldn't figure out how the camber and caster adjustment worked, so he....

...cut the K frame apart and welded it back together so the studs pointed to the side and then used shims....like the gm vehicles he was familiar with.

Really? You claim to be an engineer, yet you couldn't figure out that you simply loosen the nut, move the adjustment bar where you want it, then tighten the nut? Really? An engineer, you say?
 
YY1 said:
There was a great example of over analysis by an "engineer" over on the B body side-

An engineer (he took the opportunity to mention that several times in his posts), over in England, bought a 73/74 Charger and couldn't figure out how the camber and caster adjustment worked, so he....

...cut the K frame apart and welded it back together so the studs pointed to the side and then used shims....like the gm vehicles he was familiar with.

Really? You claim to be an engineer, yet you couldn't figure out that you simply loosen the nut, move the adjustment bar where you want it, then tighten the nut? Really? An engineer, you say?
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Sounds like a Electrical Engineer. Or one of those "Rocket Science" engineers.
 
There has been a lot of talk here about hub centering rings without any dimensional data to support their use. So how accurate is a plastic ring? So far I have seen numbers kicked around like 5 to 8 mils being good enough. Two diameters on a ring would need to +/- 2.5 to 4 mills each to make that. Seems like that is pretty tight for a piece of plastic, particularly if it is molded.
 
Mike69cuda said:
There has been a lot of talk here about hub centering rings without any dimensional data to support their use. So how accurate is a plastic ring? So far I have seen numbers kicked around like 5 to 8 mils being good enough. Two diameters on a ring would need to +/- 2.5 to 4 mills each to make that. Seems like that is pretty tight for a piece of plastic, particularly if it is molded.
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Most metal CNC'd hub centric rings have a true position between the OD & ID of .1mm (.004"). I've never had one off over .013mm (.0005")...

The plastic ones made from Polycarbonate plastic are usually about the same accuracy or close to that.

Some ABS plastic ones are .1 to .3mm (.004"-.012") off, don't buy any of them but the metal CNC'd ones.

True Position isn't given as a + or - tolerance in GD&T manufacturing. It's basically in this case the diameter of the widow the center point of the OD & ID can fall within.
 
I like data! Seems like the metal ones would perform the intended function. I was curious about the $5 Chineseium ones and if they would actually do anything or if it was just a “feel good”.
 
72bluNblu said:
Never said he was wrong about everything, I actually agree wholeheartedly with him about coilover conversions, disk brake dust shields, and quite a few suspension related topics. I love the Green Brick build, it was one of the inspirations for my Duster build. But on several occasions he has taken up positions and made claims that are just flat out false. For someone with his knowledge and resources, not to mention his influence, that's totally unacceptable in my opinion.



It's not about liking his statements, I don't care whether he agrees with me or not about anything. The fact of the matter is that he has, on more than one occasion, made claims that were just flat out factually false. The claims he made about ball joint overangling and the suspension geometry changes that would be induced by using FMJ spindles on an A-body were false when he made them. Had he bothered to actually check the suspension geometry changes instead of just going full Chicken Little, he would have known this. Mopar Muscle did in fact plot out the suspension geometry changes between the 73-76 A and 73+ B/R/FMJ spindles later and in doing so proved Ehrenberg's claims to be false- he was just speculating with no data to prove anything either way. And yet, even years after being proven wrong, Ehrenberg has continued to push his unsupported claims. In the rear disk brake upgrade he wrote up in the August 2018 Mopar Action he took a total victory lap on that old article, completely glossing over the non-existent spindle issue he made such a big deal out of and still not adding the FMJ spindles to the list of spindle swaps that work.

Same for green bearings. I understand that the first generation of green bearings had some issues, and that people did in fact have problems with them. But he still straight up harasses anyone that suggests using the new green bearings for anything other than drag racing, which is nonsense. You can check his sensationalist claims in the "tech topics" in the Mopar Action from Aug. 2018, he tells a guy to have his "friend" sign a waiver if he's going to use them. It's ridiculous. Again, I myself prefer the original tapered bearing set ups. But the new (and by new I mean now decades old) green bearing design has been proven to hold up just fine in street applications. And the simple fact of the matter is that there are millions of cars on the road that used sealed ball bearing style wheel bearings, because they're used on a great many new cars at both the front hubs and rear axle.

I get that people make mistakes and no one is perfect, I screw things up all the time. And I don't care if we share the same opinions or not. But if he keeps pushing bad information out there after it's been shown to be bad then you can't say his ethics and principles are solid. Those aren't matters of opinion, the facts show him to be wrong in those cases. I don't care if he still recommends the tapered bearings, I do too. But to imply the green bearings are unsafe is BS. Same with the FMJ spindles. If he prefers to keep the stock geometry and recommends that, great, there's justification for that. But that doesn't mean the FMJ spindles are unsafe and can't be used, or that they aren't in fact better for some applications- because they are.



Good point, those shouldered lug nut style wheels should be hubcentric. Never liked those things, but that's just my opinion.

I also like the metal hub centric ring. If you think you need one, that's what should be used. The plastic ones can absolutely be deformed, they're not going to stop the wheel from being off center. It would take doing something silly, like fully torquing the lugs out of sequence, but if you did that a plastic ring wouldn't stop the rim from moving off center. And if you do torque the 60° conical lugs as they're supposed to be, the wheel should be centered.
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Guess I can’t interest you in this w2 340 stroker motor I have ?

6C99E9DC-DB33-4B3A-B3A3-00686F6A0D33.jpeg
 
My own feeling - while hubcentric is probably the most accurate way to exist, and arguably might be the only way to go with modern low aspec ratio tires, it is totally not important using a wheel and tire package of similar design to the originals. Meaning if there's enough tire sidewall, the tire is going to make up for minor (very minor) issues cause by using the studs to line things up. My '70 E bodu has the shank lugs - not hub centric, and even with 45psi in the fronts, I never felt any issues in the car, even at 130+. Same with most of my other cars. I'm not a big fan of modern wheels and tires on these cars if I own them. So I might be a little bit jaded anyway... BUt that's where I am on it.
 
I'm in a similar boat right now ordering wheels where I need to add a spacer and want it as tight to the hub as possible in the rear - is 71.5mm the diameter of the hub for a BBP 8.75 axle?
 
I have balanced many tires and rims. The hubcentric is not nearly as close as they should be. U can see by the naked eye that they move up and down. The new way to balance rims and tires is to have a 4,5,6,7,8,10 lug adapter. U are balancing off the lugs instead of off the Center of the rim. Kim
 
toolmanmike said:
Thanks for that information. I have a pair of Wheel Vintiques Rallys on the rear of my Swinger. The center hole is bigger than the axle. Just the lug nuts keeping things centered. Those rings are the answer to that problem. I never knew they were available. Thanks again.
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My 80 power wagon has a set of wheels with a very large centre hole. Plow,plow pump and a 4D battery all up front. Its on 35’s and have never had an issue with studs holding the wheels on. I beat on that thing plowing snow.
 
Two words (OK, one hyphenated made up word) I don't see anywhere in this thread-

Uni-Lug

The whole theory and practical application is that the lugs will center the wheel so well that you don't even need the lug holes to be round- a radial slot will do just fine.
 
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