Please educate me on why a 1/4 inch wheel spacer is a bad thing

[dieck]

Ok Guys, I'm donning my asbestos underwear to ask this question, :REOutCampFire03:but I figure I'll get a more scientific and studied response here than some of the other forums. (I've searched through many of them and have not been able to come up with a solid answer).

Ok, situation: I'm upsizing tires on our sequoia and want to go with 285/70/17 bfg ATs and a small lift. I also prefer my vehicles to look mostly stock with subtle but effective improvements. So I want to keep my stock wheels which I happen to like. However, there is minor interference with the upper A-Arm at full suspension droop. I've calculated that I can give myself roughtly factory clearances with a 1/4 inch spacer as the BFGs are roughly 20 MM wider than stock and half of that will be on the suspension side of the wheel.

Now I've read many many threads about how spacers are the devil, and evil, and satan, and all that, but I don't really understand why.

So riddle me this: Assuming 1/4 inch longer studs are added, what is the phsysics professor difference between going with a 1/4 inch spacer and going with a new wheel with 1/4 inch difference in offset?

When I try to wrap my head around this, it seems that there are several metal on metal components that bare the weight of the vehicle, and I can see how installing a heavier and wider tire increases wear on the drive train, brakes, steering, etc, but I dont' understand how a 1/4 inch spacer is worse than a new wheel with equivelent offset.

Thanks for the explanation. :campfire:

 

[BogusBlake]

On hub-centric wheels, the studs don't support the shear. If you put a spacer on there that moves the wheel past the point that it's located by the studs and not the hub center, the wheel may potentially not be exactly centered on the axle.

If your Sequoia wheels are anything like my Taco's (and I think they're JUST like them), the lug nuts will fill the gap around the studs and help take the shear even if the wheel mounting surface is spaced out a little.

IMO, you'll be fine with .250" spacers. :rockon:

 

[xcmountain80]

Now Im certain someone else will chime in but there is a difference btwn wheel spacers and hub adapters. Im using hub adapters instead of shaved upper a arms. Would be the same thing you would use to change the lug pattern of your vehicle or slightly space the stance. http://www.marlincrawler.com/htm/axles.htm

I have had no problems and have heard horror stories, I run 2 sets of wheels on road AT's and Offroad MT's switch them regularly and still no problems with balance associated with the hub adapters. I am running the limitied wheels with the acorn style lugs that self center.

Aaron

 

[Scott Brady]

I am running Spider Trax hub centric and lug centric spacers. Highest quality available. If you can avoid them, do. It is just a matter of adding additional failure points.

I had an aluminum spacer fail on the Land Cruiser race truck after the event. The wheel nearly fell off in the Atlas Mountains... All of the studs sheared off. :violent-smiley-031:

 

[Scott Brady]

Oh, I added the spacers for chain clearance.

 

[gjackson]

Sweet 109 in the background!

cheers

 

[dieck]

When you say aluminum spacer failed, is it like one in the images you attached or a plain spacer that the existing lugs pass through?

Yikes. I don't like the thought of shearing all my lugs off! Please clarify!

I am running Spider Trax hub centric and lug centric spacers. Highest quality available. If you can avoid them, do. It is just a matter of adding additional failure points.

I had an aluminum spacer fail on the Land Cruiser race truck after the event. The wheel nearly fell off in the Atlas Mountains... All of the studs sheared off. :violent-smiley-031:

 

[dieck]

You are right, the taco and sequoia's wheels are the same (I've own both and swapped a couple times) I got the optional 17 inch sequoia wheels and I think they are a half inch wider than the taco 16 inch aluminum wheels. It's hard to measure though without breaking the tire off of the wheel.

On hub-centric wheels, the studs don't support the shear. If you put a spacer on there that moves the wheel past the point that it's located by the studs and not the hub center, the wheel may potentially not be exactly centered on the axle.

If your Sequoia wheels are anything like my Taco's (and I think they're JUST like them), the lug nuts will fill the gap around the studs and help take the shear even if the wheel mounting surface is spaced out a little.

IMO, you'll be fine with .250" spacers. :rockon:

 

[articulate]

When I try to wrap my head around this, it seems that there are several metal on metal components that bare the weight of the vehicle, and I can see how installing a heavier and wider tire increases wear on the drive train, brakes, steering, etc, but I dont' understand how a 1/4 inch spacer is worse than a new wheel with equivelent offset.

Thanks for the explanation. :campfire:

If we're talking about a billiet spacer like the one in xcmountain80's photo above, a spacer that's only 1/4" thick is too thin for the nuts. Look at the photo his post. With a spacer, you have a set of nuts attaching it to the lug studs; these nuts are counter sunk into the "meat" of the spacer. If your spacer is only 1/4", the nuts holding the spacer can't and won't allow your wheel doesn't have a solid surface to mount against. The wheel would be resting upon the nuts - no good.

Follow me?

In the other direction, you have "new" lug studs protruding from the spacer for you to mount your wheel. These studs tend to also be countersunk into the back side; again, a 1/4" spacer just isn't thick enough to allow them to be countersunk for a flush fit.

I hope it helps.

 

[dieck]

Yes I follow you. Thanks. The spacers that I was considering were 1/4 inch thick and have the original (longer) studs passign through them. They look similar to this although the spacers in the picture are for a different application (wrong number of holes).

I didn't want to go an inch or more out on each side as I could see how that might start stressing things more... So what do you think about this simple spacer setup?

If we're talking about a billiet spacer like the one in xcmountain80's photo above, a spacer that's only 1/4" thick is too thin for the nuts. Look at the photo his post. With a spacer, you have a set of nuts attaching it to the lug studs; these nuts are counter sunk into the "meat" of the spacer. If your spacer is only 1/4", the nuts holding the spacer can't and won't allow your wheel doesn't have a solid surface to mount against. The wheel would be resting upon the nuts - no good.

Follow me?

In the other direction, you have "new" lug studs protruding from the spacer for you to mount your wheel. These studs tend to also be countersunk into the back side; again, a 1/4" spacer just isn't thick enough to allow them to be countersunk for a flush fit.

I hope it helps.

 

[IggyB]

Using your spacer is no different than using an aftermarket wheel with a thicker center section.

 

[articulate]

So what do you think about this simple spacer setup?

Ah ha! I failed to consider that kind of design - my apologies. That's slick, and looks worthwhile. Iggy's probably right.

 

[devinsixtyseven]

read the "fastener tech" article at pirate4x4, it will help understand what the lugs and nuts are doing.

in short form, the lugs and nuts provide clamping force to increase friction between the wheel and hub. torque is transferred from the hub to the wheel or vv via that friction, rather than by the lugs resisting a shear load. when the lug nuts are loose, you lose that friction, and the lugs must support shear loads during acceleration and braking, which is why they break--they provide a clamping force, not resistance to shear. ---btw, they do resist some shear load, but it's "acceptable" load.

longer studs will strain more. more strain means less clamping force to provide friction, which forces the studs to resist more shear load.

personally i doubt 1/4" spacers are going to cause you problems, but personally i'd opt for different rims or an adapter rather than a spacer.

either way, check them religiously with a torque wrench until everything is completely seated, and never ever use an impact wrench.

-sean

 

[dieck]

Devin,

Thanks for the feedback. Good stuff. I've noticed that the lugs on the rear of the sequoia and tacoma are 1/4 inch longer than the front lugs from the factory. If so, it seems like if I used these lugs on the front with a 1/4 inch spacer they should be within engineering specs for the lugs. The track width is about 1.6 inches wider in the back of the sequoia. Maybe I'm missing something.

read the "fastener tech" article at pirate4x4, it will help understand what the lugs and nuts are doing.

in short form, the lugs and nuts provide clamping force to increase friction between the wheel and hub. torque is transferred from the hub to the wheel or vv via that friction, rather than by the lugs resisting a shear load. when the lug nuts are loose, you lose that friction, and the lugs must support shear loads during acceleration and braking, which is why they break--they provide a clamping force, not resistance to shear. ---btw, they do resist some shear load, but it's "acceptable" load.

longer studs will strain more. more strain means less clamping force to provide friction, which forces the studs to resist more shear load.

personally i doubt 1/4" spacers are going to cause you problems, but personally i'd opt for different rims or an adapter rather than a spacer.

either way, check them religiously with a torque wrench until everything is completely seated, and never ever use an impact wrench.

-sean

 

[crawler#976]

My experiance with wheel spacers is limited, but here's what I learned after using a set for 40,000 miles or so.

I used 1.5" steel spacers on the trail beater for three years. The '83 Toy front axle that I swapped in is considerably narrower that the '87 rear axle.

I had to tighten the spacers after every hard core trail run. For "normal" use, I checked them every couple months, and usually would find at least one nut loose. Sold'm two years ago, and put on 3/8" aluminum spacers over longer studs - never had a problem since.

Wheel bearings:

I tear down the front end on the beater at least once a year, usually twice a year. Admittedly the truck doesn't see the same level of use it did from 2001 to 2004, but I have noticed the front bearings are in much better shape since I no longer have the 1.5" spacers on.

Brakes:

As mentioned above, I had steel spacers on the truck. There was a very noticable change in braking effort after I put them on. In fact, that was one of the reasons I took'm off - I drove the rig as a daily driver and always hated the brakes. The extra mass also took it's toll on pads and rotors - I had to replace the rotors after only 40,000 miles and three sets of pads/rotors being turned. Part of the problems were with the braking system as a whole - adding a Wilwood valve and FJ80 master cylinder helped to balance the system again.

This is the only other first hand problems I've witnessed with wheel spacers:

My good bud had a set on a CJ-7. After a weekend of camping and wheelin some of the hard core trails off Table Mesa Rd in AZ, he had a spacer come loose and shear off the studs on the right rear while towing a popup camper at 65 MPH on the Black Canyon hill!. That was a wild ride...

Mark