viprbomber:
I again state that Toyota truck hubs/wheels have been HUBCENTRIC since at least 1996 (look at Figure 2 on attached pdf that is dated September 1996) and you will see where Toyota refers to their HUBCENTRIC wheels:
http://www.ih8mud.com/tech/tsb/Toyot...r/tsu00296.pdf
Here is also an excerpt from a Hubcentric/lugcentric discussion that was held over on the ToyotaNation forum where a lot of false information on Tacoma hubcentric/lugcentric was put to bed:
OK, here goes.
The OEM wheels like virtually every OEM wheel since the late 90's by all manufacturers are, in fact, hub-centric. There is no need to argue/dusagree on the point. For any that are inclined to disagree, it is quite easy to remove a wheel and see for yourself. The flange on the Taco protrudes about 5/16" and the OD of this fits neatly inside the bore of the OEM wheel. If you heft a wheel up to its mounting position prior to installng any lug nuts, you can notice the wheel will turn on this center hub allowing you to line up the lug nuts. The hub centric design is a sustantial strength benefit under shear forces. In shear, these forces are transmitted through the center, presumably strongest part of the wheel and the lugs do not have to absorb these forces alone.
Perhaps some confusion comes about because of the lug nut style of the Taco. The OEM nuts have a shank and washer. This is different than many cars that use a lug nut with a conical seat to secure the wheel to the vehicle.
OK, so why are Taco wheels sometimes hard to balance?
Let's look at balancers first. The most common method of balancing is to throw the wheel up on a balancer and use a cone to center the wheel. The cone goe through the center bore of the wheel. Hopefully everyone realizes the difference between a cone and a cylinder. With a cone, thee is only a circular line of contact bewtween the cone nd the wheel hub. (In contrast to the wheel as it sits on the cylindrical-shaped flange where there is a theoretical contact area of about 5/16" of depth.) Back to the balancer... Depending on the shape of the balancing cone being used and the diameter and edge shape of the wheel centerbore, the cone's contact edge may or MAY NOT be good. In some cases, it may not even come into contact with a machined edge of the wheel bore. In short, some wheel designs when combined with certain shaped balancing cones may be incompatie and you may not get a good balance. This can be easily demonstrated by removing and re-installing a just-balanced wheel to the balancing machine. If the cones do not fit properly to the wheel, the results will not be repeatable.
Car manufacturers are keenly aware of this "issue". Many manufactures - Lexus was amoung the first, require their dealership to use a Haweka-style lug-centric balancing plate. These plates use lug "fingers" and secure the wheel to the balancer using the concentricity of the lugs. Done properly, the tire/rim should be rotated while the balancer's jam nut is being tightened.
Now let's look at issues at the car itself.
Purely from a balancing perspective and explicitly ignoring other design benefits, the best combination for balancing consistency is (in order)
1. A hub-centric wheel with conical seat lug nuts. Both are simultanously centering the wheel on the car.
2. A hub-centril wheel with the shank-style lug nuts. This is the Taco OEM set-up (for aluminum wheels). The hub centricity will center the wheel and the shank-style lugs aren't quite as effective as the conical seat nuts for centering.
3. Non-hub-centric wheels with conical styly lugs. The lugs themselves must both secure and center the wheel.
4. Finally, the least desireable config is the non-hub-centric wheel with the shank-style lug nuts. In this config the shank-style lug nuts have to both secure and center the wheel... and there is too much room for error.
Being frustrated by too many bad balancing jobs, I broke down and bought my own balancer and Haweka adapter system. Consequently, I have had a lot of time to experiment.... and I also found that I have a lot more friends than I thought I had
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The facts I know for sure are that manufactures do make HUB-centric and LUG -centric Rims.
Maybe so - but I have not seen an OEM rim that wasn't hub-centic in the last 10 years or so. If you know of one, I'd sure like to hear what it is. You can consider that a challenge if you wish. I don't mind losing and learning something in the process.
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If like what you were concluding my Lug-centric is actually Hub-centric?
I hope that you, like some others in this thread, are not confusing the definition. ALL rims, regardless of bolt pattern, number of lugs, etc. have the lug pattern concentric with the precise center of the rim. A hub-centric rim is one that has a center bore that precisely fits over a flange on the vehicle. Like I said, I have not seen a rim steel or aluminum in the last 10-years that did not have this kind of fitment - called hub-centric.
The lower cost, most common, aftermarket manufacturers typically do not make hub-centric wheels. By manufacturing a hub-centric wheel, the wheel becomes specialized to one particular application or a small set of applications that share the same bore diameter. Having dealt with many,many wheel/tire modifications in both street and track applications, I personally would never purchase wheels that were not hub-centric. This is the primary reason I chose the TRD/BBS wheel for the Taco.
keezer36 - that is a good and accurate pdf link that you posted - showing that only a very minute out of round variation can cause a perceptible imbalance condition.
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I also know that you can balance a well made Lug-centric rim with the cone system. The Haweka system is NOT needed. Mine balanced out fine.
Yes, it is very possible to balance a rim with the cone system. With the right tapered cone in contack with nice machined surface of th center bore, then the balancers work as they were designed. Please note, however, that there are rim and cone combinations that just won't alow a consistent balance. A Haweka type of lug-centric balancing system will mitigate these incompatibilities.
To summarize - a rim is either hub-centric or it is not. Period. Some define a wheel that is not hub-centric as being lug centric. This is a common practice and perhaps de-facto definition. Literally, however, all rims are lug-centric.