If you search my user name you'll see, like a lot, I've been in some of the wander threads, the spring threads, and even the "swap the whole thing out" front axle threads.

Cliff Notes: after installing 2 degree steel caster shims from WFO concepts the smoke wagon doesn't wander anymore.

Moral of the story: I should have engaged my brain, basics first, it's not always an expensive and complicated solution.

I had in mind to do the 2006 axle/suspension swap this summer. I've picked up the axles and steering gear and I was putting together the remaining parts list (and cost) which made me think harder about the problem, so I dug out my alignment sheet. I had that checked and a bit of toe added right after my V spring swap two years ago. Those springs and bilstien shocks were better for the ride and the toe helped road manners but it still wandered.
Looking at the alignment range (there is no "spec") for the Ex and digging a bit into general guidance for alignment I thought there was a low cost opportunity. So I ordered up the shims and a set of 7/16" spring tie bolts (I ended up reusing my originals) and set to work. Fortunately the job was easy since it had been apart a few years before and I was done in three hours working solo. Tip: use a ratchet strap to pull the front axle to the rear when you're doing the passenger side U-bolt install, no need to disconnect the track bar.

Cruising down the road at 70-75 is uneventful now. The return to center is much better and it doesn't seem to have caused any trouble for my front driveshaft u-joint, 4x4 works fine with no vibration. I think I could have probably done the four degree shims, it would have been over the spec range but well within norms for caster.

I'm sure that if I had done this with stock springs, the wander would have been dead there as well.

Post V/C measurements (scary and demanding steering):
Left Camber: -.6
Right Camber: 1.2
Left Caster: 2.4
Right Caster: 2.0
Left Toe: -.25
Right Toe: -.26
Total Toe: -.51

Interim measurements (demanding, not quite as white knuckle unless towing):
Left Camber: -.3
Right Camber: -.1
Left Caster: 3.4
Right Caster: 2.8
Left Toe: -.03
Right Toe: -.02
Total Toe: -.05

My after WFO shim measurements (deg.):
Left Camber: -.4
Right Camber: -.2
Left Caster: 5.3
Right Caster: 5.2
Left Toe: .12
Right Toe: .08
Total Toe: .2

Turning radius and lock-to-lock are still awful, but that's for another thread.

ETA:
Watchouts:
- you'll have to drill out the center hole in the shims for the 7/16" tie bolt
- make sure you put the thick portion of the shim to the rear to increase positive caster
- clamp the springs together before you remove the tie bolt
- do your final tightening of the driver side u-bolts with the weight on the axle. The axle lower clamp is adjustable so you need to locate it to eliminate any bind in the sway bar (mount is built into this clamp plate)

Link to shims:
http://www.wfoconcepts.com/cr/3-Inch...hims/3225/4384

 

Yup, the straight axle platform is castor sensitive. It's been my believe for years that ford didn't put enough castor in and when people do the f250 spring swap to cure wander what is making the wander better is the new castor angle from the arched springs not the common believe that rear axle wrap is eliminated.

 

Interesting. Did you happen to take any pictures of your work while installing the shims?

Thread added to the tech folder.

Stewart

 

Subscribing for future reference, thanks for providing some much need solid numbers and feedback. Up until now all we've had is speculation. This'll be handy when I ditch the V/B-mod's and up to X/C-XL's - just throw some shims up front while I'm at it.

 

Maybe somebody with a factory service manual can verify the spec.
If I recall correctly it is +1.5. To +5.5

I have mine set out of spec @6* because I was experimenting with the coil spring suspension.

 

No pics, sorry. It's insainly simple, if you can swap the springs you can do this with half your brain. Just make sure you put the shims in with the thick portion to the rear!

Yes, the spec range is +1.5 to +5.5

I was a little over three as I recall, which lines up well with my results at a bit over five. If yours measures around three, I'd be tempted to toss in four degree shims. I'm not going to redo mine for it, it's OK now. Compared to the coil spring radius arm front end the '05's should have, it's never going to be as good!

I hope this info can help someone with a really inexpensive "fix" to a problem that dogs so many of these machines.

 

Fwiw. I would only use a steel shim. Aluminum shims like aluminum rear blocks can and do break.

 

caster is your friend, i used to build some pretty wild jeeps, a dana 60 front end on a custom three link on 38s can be controlled with one finger on the freeway if you give her 7 degrees of caster

 

Good data point rockhound, those big tires effectively add to the caster effect too since the taller height increases the "lever" distance between the tires contact patch and the (theoretical) point on the road thru which the ball joint axis passes.

I'm thinking that 7 with stock'ish sized tires would be good.

 

So basically its just a 2* wedge placed under the front leaf pack? Thick side of shim to rear of vehicle gives positive caster? Did you need to use a new bolt to keep the leaf pack together?

Very interested, sounds pretty easy.

 

So, this thread got me researching this topic a bit, and I came across this website, so I figured I would share.

camber bushing | Partsgeek.com

 

I am not entirely certain how that bushing is supposed to provide camber AND caster, however my front end knowledge isn't on par with others in this thread. If I remember correctly, that bushing should install in the flanges where the axle C's meet the steering knuckle - this makes sense for camber. Caster, however, I do not see being changed very much, if at all by it. Like I said though, my knowledge is ok and by no means top notch.

 

LOL, shows how much I was paying attention, I was searching castor, and ended up on camber...

I guess I need to do more research one what is what...

 

USCG, you're right. There are caster/camber "bushings" for your front axle, that can be used to dial in caster/camber. Note the difference in my first two alignment readings, both caster and camber changed. I forgot in the initial thread that they dialed in another degree of caster, you can see it moved camber too.
The bushings locate the top ball joint inside it's bore in the C. However, they are pretty limited in range, as you'd imagine that hole is only so big and keep in mind that the further you adjust up there, the further out of center your axle shaft is running relative to oil seal. A minor consideration, but one none the less.

 

You got the idea.

FYI... They do make wedges that have a slot , not a hole. I would not use those. Bolt it in place.