OK, maybe the problem we are having is the difference between how Toyota suggests the alloy wheels be mounted on a balance machine vs how they actually mount on the vehicle. I'm not trying to be difficult about this, but I still do not see any error in my logic and observations previously posted. The reason why Toyota would recommend a wheel that is centered on the hub be balanced by the lug holes excapes me. Maybe Toyota feels that the hub centering mounts on wheel balancing machines do not secure the wheel properly. Maybe it is as simple as Toyota feels that their wheels are manufactured well enough that they can be balanced on the lug holes instead. I don't have an answer for that. In any case, I'm gonna let this issue go. I still stand by my ovservations, but I'm not going to tie up any more board time debating it. All in all, a very interesting thread.

 

Just finished (literally) doing the rear brakes on my '95 4Runner (stock 15x7 alloy wheels) and they're lug centric for sure.
They may *appear* to be hub centric because of the raised ring on the hub that fits into a hole in the wheel, *BUT* it doesn't fit anywhere close to tight and does not center the wheel.
With the axle jacked up such that the wheel/tire is off the ground, it's the lugs that center the wheel not the hub, that's for certain.





Fred

 

What type of lug nuts do these wheels use, conical or shoulder?

 

Here is some interesting info, in owning a: 93 camry v6 xle and my 96 t100 x-cab sr5, both have shoulder lugs and not conical lugs. I have the alloy wheels though. No telling about the steelies except when I had a flat and used my fullsize spare on the camry the lugs fit it fine and help up. They of course didnt go in the holes as the alloy rims allow.

Both wheels are lug centric, in working in my old HS shop (5 years ago) we had a hunter tire balancer, I am not quite sure the model but it was an older one.

I balanced my camry wheels a few times. Each time I used the hub type adapter that fit in the center of the wheel and locked up tight using a vise like mechanism (it was like a giant screw where you put the wheel on) andit balanced fine and I had no problems. Now not alot of shops I notice have tis kind of adapter b/c hub centric wheels just lockup tight on the machine for the most part.

On the balance machine with the adapter they lock up just like on your car on the studs. In my expierances it didnt matter, but different machines and idiot lube/tire guys arent factored into this.

Now the t100 I had apart a few times, nope doesnt center on the hubs at all. You can put it on the hubs but you have to move it around to get the lugs to line up. I cannot fathom why yota does this other than it must offer something like strength, durability or something..

 

They're what you call "shoulder"..

The type of lug nut does not necessarly determine if a wheel is hug or lug centric.

Hub-centric wheels are centered by the center bore of the wheel matching the protruding portion of the hub, and lug-centric wheels are centered simply by the position and diameter of the lug bolts.

The type of wheel determines which type of lug nut to use, not if the wheel is hub-centric or lug-centric.

Steel wheels almost always use a conical type lug nut, regardless if they are hub or lug centric. That's mostly because of the lack of thickness at the mounting area of the wheel. Steel wheels, at the mounting surface, tend to be a lot thinner than alloys.





Fred

 

I would have to disagree with that. By design, the conical lug nut forces the hole in the wheel (steel or alloy) into exact alignment with the lug stud. Therefore, by design any wheel that uses conical sug nuts has to be lug-centric. The shoulder type lug nut, which uses a washer to contact the outer surface of the wheel hole can't determine the exact alignment between the lug stud and the hole in the wheel because there is too much play between the diamater of the lug bolt and the diameter of the wheel hole. The center hole in this type of wheel, which is machined to match the diameter of the center hub on the vehicle, determines the alignment of the wheel to the vehicle (hub centric). The shoulder lug nut is only securing the wheel to the vehicle on a hub centric wheel. Many older, and many aftermarket alloy wheels use conical lug nuts and have hardened conical inserts in the wheel holes. This type of alloy wheel is still lug centric, not hub centric.

 

I totally disagree with you, the hub centric wheels that use conical lug nuts still use the hub to balance off of when mounting the wheel on the studs. The studs have no part in balancing it on. The lugnuts do nothing to balance them on at all, the wheels still fight tightly ont he hubs with little play compared to the lug centric wheels.

Not really so, the lug nut goes further into the stud than the conical lugs do (1/4" or so into it) and thus hold the wheel in alignment with the studs through the lugs and not the hub at all.

Not really, the yota wheels arent machined to fight the hub tight and if you think about it how is the hub centric wheel is lug centric if it still balances off the hub? The shoulder nut is not used on these at all either.

Hardened inserts in the wheels? Since when?

This type of wheel is still hub centric, if it balances off the hub its hub centric.

We can argue all day about this but the fact remains-any wheel which does not fit the hub tightly and uses shoulder lugs is lug centric and any wheel that does ifit the hub tightly and uses shoulder nuts is hub centric.

 

10-4..




Fred

 

I'll try this one more time, though I'm probably wasting my time.

First off, if you want to read about real automotive engineers discussing this issue, check this site out. There are some side issues raised, but the issue of hub centric vs lug centric are pointed out;

http://www.eng-tips.com/viewthread.c...=152939&page=1

"I totally disagree with you, the hub centric wheels that use conical lug nuts still use the hub to balance off of when mounting the wheel on the studs. The studs have no part in balancing it on. The lugnuts do nothing to balance them on at all, the wheels still fight tightly ont he hubs with little play compared to the lug centric wheels."

By the very definition, you can't have a wheel that is both lug and hub centric. You can't have a wheel that is hub centric by design have lug centric conical lug nets.

"Not really so, the lug nut goes further into the stud than the conical lugs do (1/4" or so into it) and thus hold the wheel in alignment with the studs through the lugs and not the hub at all.

How far the lug nut goes onto the stud has nothing to do with it. It is how the lug nut contacts the wheel hole. The ONLY way a shoulder type lug nut could determine an EXACT alignment with the wheel hole is if it was of the exact same diameter as the hole, and then you wouldn't be able to install it. Because there is a difference between the diameter of the houlder lug nut and the alloy wheel hole there is room for movement. The movement means you CAN'T have an exact alignment between them.

"Not really, the yota wheels arent machined to fight the hub tight and if you think about it how is the hub centric wheel is lug centric if it still balances off the hub? The shoulder nut is not used on these at all either."

There are "yota" wheels that are machined to (fight) the hub tight. My '03 has the factory 17" alloys, and the center hole on the wheel is machined to fit the hub very tightly when the shoulder lug nuts are tightened. That is why many people have a tough time removing alloy wheels that have been mounted for some time even when the lug nuts are removed. If the wheel does not fit the hub tightly, it can't by definition be hub centric.

"Hardened inserts in the wheels? Since when?"

Apparently you haven't seen very many aftermarket and early alloy type wheels. Just think about it, the aluminum alloy that many of these wheels is made of is too soft a metal to take the pressure and abuse that conical lug nuts would exert on it. That is why they either have hardened conical inserts in the wheel holes, or a center hub plate with the wheel holes of a different material that the rest of the wheel. (I suppose you havent' seen this type of wheel either).

"We can argue all day about this but the fact remains-any wheel which does not fit the hub tightly and uses shoulder lugs is lug centric and any wheel that does ifit the hub tightly and uses shoulder nuts is hub centric."

You can't argue with the facts, and you aren't using facts. If you understand how mechanical functions work, you wouldn't be arguing about this at all.

 

As I've posted (above) already.
My '95 4Runner has stock 15x7 Toyota alloy wheels.
They do NOT fit the "centering ring" on the hub anywhere close to tight.
After installing the wheel you have to move it around quite a bit to get the lug nuts started (what you call shoulder style).


The lug nuts CENTER the wheel...
There is no way to deny that.
The centerbore isn't even close to the size of the raised area on the hubs.

These are LUG CENTRIC wheels......
The lugs not only center the wheel, they also bear the weight.

The wheel type really is what determines the lug nut type, not if the wheel is hub or lug centric.


Fred

 

Up until your last statement (The wheel type really is what determines the lug nut type, not if the wheel is hub or lug centric."), you are stating EXACTLY what I have been trying to make clear. But, I would ask you to be sure about which type of lug nuts your wheel is using. If the lug nuts have a tapered or rounded surface on the end where it meets the same type of taper on the lug hole in the wheel, then it is a conical style lug nut. A shoulder type lug nut has a straight shank which fits inside the lug hole on the wheel, and usually a flat washer attached to it which actually contacts the front edge of the wheel lug hole. The only purpose this type of lug nut serves is to fasten the wheel to the axle, not center it. As I have been stating all along, if you have conical lug nuts, they determine how the lug hole on the wheel is to be centered around the lug stud. It's really quite simple. When the lug nut is threaded onto the lug stud, it centers itself on the stud. When the conical surface on the lug nut contacts the matching conical surface on the wheel lug hole, it causes the two to align along the center line of the lug stud. Do you see any flaw in that logic? Now apply that principle to the rest of the lug nut/studs on the wheel. It doesn't matter if you have a 3, 4, 5, 6, or 8 lug wheel. If your wheel is designed to use conical lug nuts, they determine how each wheel lug hole is centered around each lug stud. The size of the center hole in the wheel, and how it fits the center hub on the axle is immaterial. This type of wheel is lug centric.

When Toyota, or any other manufacturer, design an axle hub, the don't specify (in most cases) which type of wheel the hub needs. They manufacture the axle hub to take either type of wheel, lug centric or hub centric. The center hub is machined to center around the center line of the bearings, and the lug studs are also centered around the same centerline. Therefore, it is the design of the wheel that determines how it is to be centered around the same center line of the bearings. If you look at the sites of wheel manufacturers, they will specify which type of lug nut is to be used with each wheel, depending on how it is designed.

So in your last statement "The wheel type really is what determines the lug nut type, not if the wheel is hub or lug centric." the first part is true, the second part is not. Both lug type, and how it is centered on the axle is determined by how the wheel is designed.

 

Techwrench is 100% correct. Very solid information to back up his statements. He has thrown out some pretty solid information. I find humor in the statements that say he is wrong just because. You people scare me.

And for those that are trying to make the misinterpretation from the issuing of the TSB, need to know why they put the TSB out in the first place. It is not because the wheels are lug centric. The way the wheel mounts on the hub has nothing to do with the way you balance it. The problem was the design of the wheels made it impossible to back cone them and with the standard large cone it was difficult to front cone accurately. They have since come out with a cone for the Toyota center bore so you can front cone it and get it to center.

 

I am under the impression Toyota/Lexus are all lug centric, but I think this thread will go on forever with no real definite answer.

My advice: get them balanced as if they're lug-centric first, and if that doesn't work try hub centric.