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

[dieck]

Mark,

Thanks for the feedback. Good stuff. It sounds like based off of your experience, the smaller pass through spacers were less of a problem than the 1.5 inch double lug spacers. This is in line with what I was thinking but it's good to hear real world affirmation.

-H

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

 

[devinsixtyseven]

do you remember if it was the original lugs that sheared or the lugs on the adapter?

i have a set of 1.5" steel adapters from aor4x4.

after hearing all the freakish stories of sheared lugs and whatnot, i figured these would be a temporary solution and i'd check them regularly.

the first thing i noticed is that the lugs on the adapter require a finish torque, then another, then a trip around the block and a finish torque, then a trip down the road and a finish torque, etc...

it's like the lugs needed to be strained, or seated, or something. i kept the torque wrench in the truck, and every time i parked, i checked the lugs. it took about a week of this, now they're fire & forget...tho i do check them still. theyre solid...

as for the internal lugs and nuts, they have been solid from day one. i torqued them in place, mounted up and went for a drive, then took off the wheels and checked the adapters. i did this a few times over the first month or two, and the interior nuts were never, ever loose...just the exterior lugs/nuts seemed to need to be properly seated. i'm confident enough with these adapters theyre getting reused for a project in the near future.

not sure how the bearings are holding up...theyre unit bearings. the inside track width hasn't changed, just the outside track width...there's about the same amount of space between the upper control arm and sidewall as there was stock, fwiw.

incidentally arent dually wheels a similar setup? or do both wheels mount to the hub?

-sean

 

[Pskhaat]

Only topically mentioned above, but your bearings are designed for the stock wheel offset and you will artificially adjust bearing load.

BUT: steering geometry and pivot points to maintain the Ackermann angle wants to place the center of the wheel in line with the imaginary line drawn through the kingpin bearing centers (on live axle) to the ground. When you add larger tires, that moves that ground pivot point outward from the center of the tires which can be corrected by spacers. Though not the same in IFS, the concept remains.

So...you will help adjust for the steering, but put additional moment on the bearings.

 

[dieck]

Thank you for the response. If I understand your post correctly what you are saying is that the act of putting larger tires on the truck (whether spacers, or an equivelent offset wheel is used) increases load on the bearings? Whether the fitment of the tire is positioned with a spacer or with a wheel, as long as the total offset is the same, the load on the bearings is as well. The load is increased because the tire is moving away from the bearing increasing the torque it applies to the bearing. (I'm picturing my highschool physics teacher doubling his torqe by increaseing the length of the lever).

Only topically mentioned above, but your bearings are designed for the stock wheel offset and you will artificially adjust bearing load.

BUT: steering geometry and pivot points to maintain the Ackermann angle wants to place the center of the wheel in line with the imaginary line drawn through the kingpin bearing centers (on live axle) to the ground. When you add larger tires, that moves that ground pivot point outward from the center of the tires which can be corrected by spacers. Though not the same in IFS, the concept remains.

So...you will help adjust for the steering, but put additional moment on the bearings.

 

[devinsixtyseven]

yes, that is correct.

however, with ifs, the center of the contact patch is generally a good half a foot from the center of rotation. even on a solid axle, the center of the contact patch is laterally displaced from the kingpin...not much, but it's there.

a quarter inch, or even 1.5", wont noticeably change your ackermann angle...youre talking about a difference of 1.5" to a 30'+ radius (about 35' on an older taco, about 40' on a new taco or older tundra).

-sean

 

[Pskhaat]

the load on the bearings is as well.

It's really the moment applied to the bearing and I should have been more clear. The bearing from the factory will have it's load applied at some moment (not time ), adjusting offset will adjust the moment to the bearing. Nothing that thousands of off-road folks havn't done anyway with complete success and no worries, just true nonetheless.

 

[Pskhaat]

wont noticeably change your ackermann angle...

True also, but my FJ40 is 35" shod with consistent offset, and though the caster and toe are correct, it's much harder to steer with my factory offset vs when spacers were applied (taking into account the steering problems introduced with the lift and larger rubber).

The 40 is non-PS, but I would guess the PS may work a tad harder.

All of this said, I'm thinking about 1/4" or 1/2" on my Hundy soon... :smiley_drive:

 

[devinsixtyseven]

sure it's not just the larger contact patch?

i wont even turn the wheels, unless i have to, in place if i'm on the brakes. just too much stress on the steering components...i can hear the p/s pump whine. i usually set the e-brake, throw it in neutral, and steer with the hubs open if i have to make a sharp, stationary turn...it's not worth stressing the steering components.

 

[DaveInDenver]

I read through this thread, but haven't really seen this point. I would avoid like the plague using a spacer like this that relies on the stud coming out of the hub. Your wheels are held in place by the lug nuts and studs, but the friction of the wheel against the hub face is what actually keeps them from twisting when you accelerate or brake. The nuts and studs only provide the force holding the wheel/hub interface together, they don't provide any rotational resisting force. IOW the studs are only supposed to be in tension and not sheer and by adding a spacer you double the number of interfaces that can potentially move. This is bad, wheel/spacer/hub movement tends to sheer studs in a hurry. This is particularly bad when it happens in a panic stop situation.

The only spacers that I would trust are ones that are steel and bolt directly to the hub with a second set of studs for the wheels. Those are usually much thicker than a 1/4", though. IMHO, if you need a 1/4" of additional clearance, get wheels with less backspace or more positive offset. My personal feeling is to avoid spacers at all cost unless there is simply no other option.