Wheel Alignment Frustration

[cplynn]

Finally got my Bronco back on the road and took it in for an alignment yesterday. I went to an Eagle Automotive near where I live and they told me they couldn't do it, stating my axle is shifted to the driver's side, but they didn't tell me how much. I installed a Duff's 3.5" suspension lift kit last spring, and I'm thinking maybe when I was reinstalling the radius arms the axle shifted and I didn't realize it. Not sure. What's the best way to measure if and how much the axle is shifted? Also, when looking at the front of my Bronco, it looks like I have significant positive camber. Is this typical after installing a suspension lift? I'd like to get a printout of my toe, caster and camber to find out where everything is at.

I got the impression this shop was hesitant to even do an alignment on my Bronco with the upgrades that have been installed. Has anyone else had the experience of shops being hesitant to do an alignment on your modified rig? Eagle actually suggested to me to go to a 4x4 shop to get the alignment done. In addition to the suspension last spring, I also installed a Chevy disc brake conversion, new ball joints, new tie rod, adjustable drag link and Duff's adjustable trac bar. So, a lot of the front end and steering has been upgraded.

[Kinder]

I’ve got to say that most shops shy away from older vehicles, they can’t just plug them in and be done. I’ve had mixed results with the local Firestone here in Parker with older vehicle alignment. They only have one guy that’ll do them, and then he charges outrageous fees.

For a Bronco it’s even worse since the only adjustment that can be made without taking the spindles or radius arms off is toe in. You can measure from a reference point on the frame out to a reference point on the axle to check your offset. If needed I’d recommend an adjustable track bar to correct a significant problem. Camber isn’t usually affected by a lift, but if you swapped out your knuckles when you did the disc brake upgrade along with new ball joints it could have thrown your camber out. There are shims for ball joints and shims for the knuckle to spindle mating surface (the shims at the knuckle are almost imposible to find new, that’ll be a junkyard hunt).

I’d recommend a new shop, maybe Big O, they are friendlier here in Parker, and get the print out so you can start tackling the problem. If you don’t want to or can’t find a shop I believe Jason (Crawlercreations on the forum) can help you out, he has an alignment rack at his shop in Arvada.

[Digger]

Finally got my Bronco back on the road and took it in for an alignment yesterday. I went to an Eagle Automotive near where I live and they told me they couldn't do it, stating my axle is shifted to the driver's side, but they didn't tell me how much. I installed a Duff's 3.5" suspension lift kit last spring, and I'm thinking maybe when I was reinstalling the radius arms the axle shifted and I didn't realize it. Not sure. What's the best way to measure if and how much the axle is shifted? Also, when looking at the front of my Bronco, it looks like I have significant positive camber. Is this typical after installing a suspension lift? I'd like to get a printout of my toe, caster and camber to find out where everything is at.

I got the impression this shop was hesitant to even do an alignment on my Bronco with the upgrades that have been installed. Has anyone else had the experience of shops being hesitant to do an alignment on your modified rig? Eagle actually suggested to me to go to a 4x4 shop to get the alignment done. In addition to the suspension last spring, I also installed a Chevy disc brake conversion, new ball joints, new tie rod, adjustable drag link and Duff's adjustable trac bar. So, a lot of the front end and steering has been upgraded.

Best way to measure axle shift is getting a plumb bob and measuring from a fixed point on each side of the frame to a fixed point on the axle and subtract the difference.

Shop around, there are shops that will align an old Bronco, but they are so simple you could do it at home if you have a level surface.


https://www.speedwaymotors.com/Search?query=caster%2Fcamber%20gauge&facet=GA_Nav_Part:Caster%2FCamber%20Gauges

[B.O.B.]

When I lifted mine I did pretty much what Digger said. I measured from frame to inside of tire. If you have a buddy it’s nicer. Then just kept adjusting the trac bar until I got as close as possible. Never adjusted anything else as I didn’t change steering.

[mickphatmac]

Take a picture from the front of the suspension include tie rod ends and drag link, that would be a good place to start.
I took mine to Les Schwab and they told me my drag link and tie rod ends were worn out and wouldn’t do it, so I bought the adjustable ones, and after I installed them I noticed that they weren’t parallel so I went from a 4 inch drop Pitman arm to a 2 inch and then they were able to do my alignment!!
Post your picture.

[cplynn]

Here's a picture of my front end.

[Jesus_man]

Looks like you have everything to adjust it yourself. I believe the correct order is:
1. Center the axle under the frame by adjusting the track-bar.
2. Adjust your caster as necessary with new c-bushings.
3. Adjust your toe by adjusting the tie-rod.

[cplynn]

Took my Bronco to a Firestone yesterday and they were able to do the alignment. While my steering feels better than it did before, I feel like once I get to 35 - 45mph my Bronco starts to wander in the lane, and I feel like I have to fight the steering wheel a little bit. I've attached the printout they gave me after doing the alignment. Is it the caster that might be affecting how my Bronco handles? Curious what thoughts are on these numbers and how I can make corrections if needed.

As noted in my earlier post, I installed a Duffs 3.5" suspension lift last spring and if I'm remembering correctly it came with the 7 degree C bushings, which I thought was supposed to help reduce or correct any caster change caused by the suspension lift. To improve my caster would I just need to get different degree C bushings? Or maybe extended radius arms?

[Jesus_man]

I hope I am not misspeaking here, but Toe & caster are the two major contributors to "wandering".

It has been a very long time since I've dealt with C-bushings, but IIRC there is a top and bottom and putting them on in reverse would make your caster worse. Perhaps start there, but know that once you loosen up the clamps, you have lost any adjustments just performed by the shop.

You can check your toe at home. I am not sure what the degrees would translate to, but you want them to be pigoen toe'd between an 1/8" and 1/4". I can find an article to explain the process if you want.

[Gunnibronco]

I think JD is right, your caster is off, and that would help a lot. I would check the c-bushings, they should be labeled for orientation. 7* bushings is the most correction available. If that doesn't help you are into long arms, T-Rex arms, or more invasive adjustments. I don't know what caster a 3.5" lift with 7* bushings should have but it should be better than that.

Hopefully Digger can chime in about the rest. The factory camber is based on bias ply tires and he recommends modern camber specs. Then to complicate matters there is a preferred cross camber to compensate for road crown.

I'm curious how the old school 1/8"-1/4" toe in translates into degrees. I think tire size would be a factor in that calculation. A larger tire at 1/4" toe in would be a different angle than a smaller tire.

I've been looking at my alignment (using a digital angle finder), and reading some, but I don't want to gum up your thread with my info.

[Digger]

Factory camber is 1.50 degrees positive (top of tire tipped outward)
Factory caster was something like 2-4 degree range.
Total toe was 0.25 degree positive

Old cars were built with bias ply tires and usually non-power steering. Caster was low to negative, which reduces steering effort. Back then you could get away with negative caster because vehicles had larger steering axis inclination, which produced the same straightening effect that positive caster does. Cars were designed with straight-line performance and ride comfort. Positive camber moves the center of the contact patch close to the steering axis intersection with the road, lowering steering effort and reducing road impact's effect on the steering wheel.

Later radial tires came about and improved ride quality, but sacrificed lateral performance. To compensate, cars were built with slight negative camber. This keeps the tire flat against the road while cornering. At the same time, power steering became commonplace and as a result caster was increased to provide proper return-to-center. The extra effort to turn the wheel was negated by the power steering.

Modern specs for a Bronco look like this:
Camber: 0.00-0.25 degree positive
Caster: 3-5 degrees positive
Total Toe: 0.25-0.38 degrees postive.

Tire wear angles are Toe (greatest influence) and Camber. Caster has no effect on wear. Large amounts of cross-camber could cause very small amounts of wear.

Some things that stand out with your alignment:
1) your caster is low. 7 degree bushings usually get you back into spec after a 3.5" lift. If not, you will need drop brackets or modified radius arms.
2) Your left camber looks normal for the factory, right camber is off quite a bit, so something may be slightly bent. Not uncommon with these old trucks.
3) Toe is dead on.

The only way to adjust camber is with ball joint sleeves from a company like SPC. They replace the lash adjuster and offset the upper ball joint. You will probably want to install a 1.25 degree sleeve left and .50 degree right. Keep in mind you don't want perfectly zero camber otherwise the truck will wander. Some positive is a good thing. I would buy more than one if you go this route. The threads are cut randomly oriented to the taper angle. If you play around a bit, you can get a sleeve that tightens the lash right as it's hitting adjustment. Camber can be adjusted at home using a bubble gauge. I did this with mine while the axle was out of the truck.

As mentioned above, Caster is adjusted with C-bushings. I recommend 7 degree units.

Toe is adjusted with your steering tie rods. Toe can be measured with a tape or bubble gauge at home. With tape, you will have to do a little Trig.


More advanced bits:

TOE: I set my toe to 0.25 positive. This is pretty standard and works is most cases. However, if you have really wide tires or offset rims that produce lots of scrub radius, your tires can dynamically toe-out when driving, resulting in reduced toe and wandering. Stronger tie-rods or increased static toe compensates for this.

CROSS CAMBER: While there are design limits, variation within those limits can cause the vehicle to pull left or right. This can be used to your advantage. If everything was straight, even and perfect, your Bronco would likely drift to the right due to the crown built into most roads. Good alignment guys (usually the old ones) will build in .13 to .25 degrees of cross camber. Remember the vehicle will pull to the side with greater positive camber. On my rig, I'm .38 left and .20 right and it drives straight as an arrow on the interstate.

CROSS CASTER: Same effect as cross camber, but less effective. It become more effective with greater SAI. With cross-caster, the vehicle pulls to the side with less-positive caster.

POSITIVE CAMBER: The reason for running non-zero camber is to pre-load the tires a bit and prevent wandering. Think of a bicycle. If you lean a bit, the bike turns. If the front tires are leaning in or out, they want or travel in a slightly non-straight line. When they are opposite each other, it side loads the tire just enough to provide stability. The camber can be negative or positive, doesn't matter. BUT I prefer slight positive, because it lowers the maximum lateral force a tire can generate and increases the likelyhood that in an extreme turning maneuver like avoiding a deer, that the front end will break traction and skid (plow) vs hooking up and rolling the vehicle.

[Jesus_man]

Did some CAD doodling. With 35" tires, the angle at 1/16" toe is .205*. With a 1/8" toe it's .409*. The measurement is per side, which is how the alignment figures come in.
If this is a "rule of thumb" for stock 29's, the figures are as follows:
1/16" toe is .247*
1/8" toe is .494*

So, using Digger's figures, you need to be at or slighly more than that 1/16" toe in (1/8" total) on 35" tires.

[Gunnibronco]

Awesome info guys. Appreciate the knowledge and calculations.

Sent from my E6910 using Tapatalk

[cplynn]

Yes, great info guys, thanks for the input. Currently, I have 33" tires, but will be going to 35's at some point, hopefully in the near future. I'm going to start by checking my C bushings and make sure those are in correctly. I'm going to be upset if they aren't because I really thought I paid extra special attention to the orientation when I installed them to ensure I got them in correctly! I'll post my findings when I'm done.

[cplynn]

Here are pictures of the front and rear C-bushings on the passenger side. I believe I have them installed correctly. The arrows point to the degreed lip on the bushing and I confirmed these are 4-degree bushings. Driver's side bushings are installed the same way.