I did some researching on the topic and I have found two opinions. One is that whether you use a wheel spacer or rims with an offset that pushes the tire out, the affect on bearings is the same. The other is that spacers affect the bearings more than a custom wheel.

If the affect is the same, than would using wheel spacers with a wheel with more backspacing to bring a wheel/tire combo back to a stock location have a zero affect on bearings?

If that's the case, than what we really need to consider when choosing Wheel/tire combinations affect on bearings is how much further the combo stick out from stock and how much more weight the new combination has over stock.

Am I missing something?

 

I'm kinda missing what you're looking for, best way to have a zero effect on bearings is simply not installing them.

I think backspacing is preferred over wheels spacers simply because one less piece in the equation.

I chose wheel and tire combo for intended use of my rig. DD and capable trail rig. I like to drive to the trails and drive home, not knocking trailer queens just not for me.

I had to run wheel spacers on the front after SAS, but found with increased flex that rear tires rubbed frame rail thus limiting rear flex with IFS backspacing. So I run wheel spacers front (wider) and rear.

Yes this setup increases leverage of load of vehicle on bearings. Next set of rims will have less backspacing to push tires out and eliminate need for rear wheel spacers.

With my current set up the biggest killer of wheel bearings has not been wear but seal failures allowing contaminants into wheel hubs. Truck sat for years.

This is just my experience.

 

On a few other 4wd forums, there was a consensus that your bearings don't know whether the wheels are being pushed out by wheel spacers or by a wheel that has less backspacing to get the same effect. That was what most people thought. However, I did find a view that was substantiated with some facts that the proper wheel to get the offset needed is better than using a wheel spacer.


The idea that wheel spacers can fail is true, but my belief is that is caused by a cheap wheel spacer or improper install. I have TG spacers now and if I buy again, I would go with TG or All Pro.
I'm not worried about a wheel spacer failing.

I wish I had saved the links to some of the discussions. There was one that talked about how the bearings were designed to take a 50/50 split of the vehicle weight and how moving the wheel out changes that dramatically. That's a better visualization of why a spacer or wheel does not matter. The weight coming down on the bearings will be affected the same.

My old setup is not a good example because I had 35x12.50x15 tires on 15x8.5 wheels with 3.75 backspacing.....and then I added 1.5" wheel spacers!
With that setup, my tire was sticking out 3.5" more than stock. That was too much and my bearings paid the price, but that was a combination of bigger tire, wheel spacers, wide rim, and low backspacing.

I dropped down to 255/85/16 tires on IFS rims that have 4.75" of backspace and with the narrow tire, narrow rim, and the 1.5" spacers still on, the tire is barely outside the fender and only 1.22" more than a stock setup. In my new setup, the effective backspacing with the wheel spacer is 3.25" comparred to stock of 3.375", which is a negligible difference. I'm actually wanting to put on 2" spacers to set the wheels out 1/2" more, but even with a 2" spacer the effective backspacing would only be 3.75" and the tire would be sticking out 1.25" more than the original stock setup.

I just wanted to start a discussion on here that doesn't end with "wheel spacers are bad" which seems to be more myth than fact.

 

What I didn't like about wheel spacers...

My wheels were no longer hub centric. Not only that, but the spacers were not hub centric either. So the wheel was not centered, causing vibration on the highway. This was on our Sequoia, which was our daily driver and saw a lot of highway use.

For a primarily off road rig, it would probably not matter much. I still prefer to have a wheel that fits the way I want, without spacers.

 

^pretty sure that hub-centric wheel spacers exist.

I've always assumed no-spacers was the ideal setup, but if you have to use them then use the ones that bolt on separate and don't share the same wheel studs. Pretty much any "overhang" or pushing the tire/wheel edge further outward than stock setup is putting extra leverage on bearings/axle - so that's pretty much all of us here who don't have stock 28" tires

 

Toyota 4x4 are lug centric. Chevy is hub centric.

Just don't forget to retorque wheel spacers. A little blue loctite never hurts.

Many factors can cause wheel bearings to fail beside backspacing/wheel spacers.

 

Put the wheel on that fits they way you want. Worst case is you have to replace bearings a little more often. On a correct factory offset you can get 100k easy, if not more. Push way out.... life is shorter.

Go for the look you want, and maybe you pay a little rent.

 

I should have clarified that the wheel spacers I am referring to are the bolt on type with their own studs. If you are going to use wheel spacers, and I am currently, then get this type from a mfr with a good reputation. You can find cheaper ones on ebay or Amazon, but this is not an item that I would want to cheap out on.

An interesting note is that even the wheel packages that Toyota would offer would have a negative effect on bearings, but not enough to beef up the bearings on the trucks with the 31" tire optioned.

Like Muddpigg said, many factors are in play. I think we are fortunate that our trucks were overbuilt and can take the additional stresses we put on them, but even our tanks have their limits.

 

weight is indeed a part of the equation, the forged beadlocks that i ended up with were lighter than factory steel wheels, if i remember correctly, and i got the lightest 37" radials that i could find, wrangler mtr's.

it's still about 125lbs a corner.

i fixed the seal problem with those new hubs from tg, the seals ride on clean metal now, not a rusty pitted surface.