71 Bronco Alignment Results/Ride Improvements

[Broncostang]

Wanted to get some feed back on the results from alignment shop specs. Late model 71 302 3spd, all new steering components, c bushings, 2.5 suspension lift w standard shocks, 1” body, new power steering, tires inflated around 28 psi. It rides ok, although has a slight shimmer or wandering at times which I would like to resolve before I take the family for drives. I was thinking upgrading shocks with eibach, or the hellwig sway bar. Any other suggestions?

 

[Broncostang]

Here’s the alignment results and pictures of the suspension.

 

[DirtDonk]

What size tires?
Wandering is not usually a result of the shocks doing anything wrong. But toe-in, tire and wheel specs, trackbar issues and wheel bearing issues are some things that come to mind.
The angles of your draglink and trackbar are looking pretty steep for the amount of lift, but that could also be the camera angle.

Have you measured between the top of the axle and bottom of the frame to verify the amount of lift you actually have?

 

[Broncostang]

I have 9” between the top of axle housing and bottom of frame, tires are 315/70/17 Micky Thompson Baja Atz, I’ll attach another photo direct shot.

 

[DirtDonk]

Consistent and within spec of a 2.5" suspension lift.
The angles look better in that pic. Still steeper than optimum, but that's what you get with 2" or more of lift. So not a dire condition.
I'm for using dropped pitman arms and trackbar brackets with even just 2.5" of lift, but it's not an absolute necessity.

Toe-in is still worth checking. You're listed at .05" per side but that seems a bit shy to me.
Most modern equipment gives readings in degrees, but yours says specifically "in" which says inch to me. But either way, it seems light in the toe department.
Is that roughly 1/10" or so? Factory spec is between 1/8 to 1/4 inch toe-IN. With 3/16" being nominal at least with stock tires.
Yes, it "might" change with different tires, but I've actually found 3/16" to be pretty darn good with various tire and wheel combinations.

So like I always say, you can easily experiment with toe in your driveway with minimal tools or experience.
A small twist of the adjusting sleeve can make a notable difference in how it feels both around town and on the open road.
Might be worth a try in this case. Trying to narrow down a wandering feeling is right up the alley of tweaking with toe-in settings.
It also can make a huge difference in how "loose" it feels while driving.

Give it a shot at least and see if anything changes. The good thing about toe-in changes is that they are super easy to return to where it was before you messed with it.
Just a quick turn of the screw, so to speak.

And now might be a good time to confirm the tire manufacturer's specs. Do your tires measure 34.6" tall with the vehicle weight on them?

Paul

 

[Broncostang]

Thanks for the advice, so would sway bar help any drivability when tracking straight down the road? I can take my hand off the wheel and tracks straight, but when I hit some uneven areas, it tends to move side to side. Measurement on the Baja atz 315/70r17 are around 33-5/8” when I square off the top of tire, while vehicle weight.

 

[ngsd]

What degree c bushings did you put in it?

 

[Broncostang]

7 degree c bushing

 

[Digger556]

Here’s the alignment results and pictures of the suspension.

Your camber is fine, your caster is fine, but your toe is low. Measuring toe in inches is a very old-school way of going about it, but it equates to about 0.1 degrees for a 29 inch tire, like what would be stock. For a bigger tire, 0.10 inch in is even less in degrees.

You really need about 0.25 degrees of total toe-in. With bigger tires like yours and smaller (stock) steering components, you may need more. With bigger tires or large rim offsets, your tires will tend to toe-out when driving due to the drag of the tires x large scrub radius. This requires more static toe-in to combat this and remain stable at speed.

Increasing caster will help your stability, but it is not required. I was 37s at interstate speeds with 2.5 degrees of caster and it was fine. (now at 4.5 to improve return to center) 4-5 degrees is recommended for your setup.

With Toe or Camber, zero degrees will result in an unstable drive. Having some toe or camber creates a slight bias that stabilizes the vehicle. Think about 2 people standing straight up on a windy day, their bodies will sway slightly in the wind, but if they lean on each other slightly, they will be more stable.

 

[DirtDonk]

Thanks for the advice, so would sway bar help any drivability when tracking straight down the road?

Yes. Sometimes…

I can take my hand off the wheel and tracks straight, but when I hit some uneven areas, it tends to move side to side.

This is consistent with the previously mentioned steeper angles of the track bar and draglink.
Lowering the angle usually reduces the effect.

 

[Broncostang]

Thanks for the help, I’ll adjust the toe in some and go from there.

 

[DirtDonk]

Even though you just have a single adjuster, go slowly and turn it maybe 1/4" or 1/8 turn at a time. Or even less...
Then drive it for as long as it takes for you to get a feel for it.

I used to give it a turn and daily drive it for a week, but nowadays I can usually feel it within a few miles or at least the same day. Making my corrections much quicker than before.
I did my last test on my '68 last year, running from as much as 1/4" toe-OUT to almost 1/4" toe-IN. For now I settled on the roughly the same 3/16" that has always seemed to work for me.
I actually could not tell the difference this time between 1/8 and 3/16 inch this time, like I could previously. But both are decent and I'm still working on other aspects for now.
At least you have a starting point from the alignment sheet. I did too, but it was in the "degree" increments mentioned previously.
Made me have to do math!

Paul