Cross Steer... Bump Steer solution?

Well, I'm into the next realm past my second axle flip....
I still have what I consider pretty bad bump steer....

What I'm going to attempt to do to fix it is to build and install a cross-steer setup to bypass drag link geometry issues....
The cross-link will be parallel to the ground and nearly four feet long so there will be little arc of travel vertically at the passenger-side end.....
I have already posted some pictures of bell-crank fabrication in my "Axle Flip 2.0" thread, but will post subsequent pictures here because it's really a new project....

Here, I've cut the center hub hole and drilled two of three mounting holes in one of the aluminum spacers...Once all of the holes are accurately cut, I cut the outside shape...





This big circle of 1/4 inch aluminum was the leftover from fabricating my fan shroud....I have the coles cut for one shim and a second marked out for drilling...






I start with the hole saw cut and next, the hole right above it....After that I bolt one of the previous pieces to it to use as a pattern to drill the other two holes...





Here, the hub with the arms on it is hanging in place and I have a piece of angle tied to the existing drag link to determine length to order and to check if enough range of motion is available...

wow!!! you do awsome work sir!!

If anybody reading this has a front axle laying around that has the steering arms bolted to the spindles....
I'd like to buy a pair of these arms before I modify mine in a way that can't be reversed....

I've been transparent about the good, bad, and ugly of every modification I've done on this van and I want the front lowering to reserve the possibility of being undone and I've come to the point where I need to buy some parts to keep that option open.....

Thanks to Eric Frahm from the FB Vintage Chevy Vans for putting a couple of steering arms in the mail for me today.....His are actually for a 64 van, so we will see if there is differences.....

Here are a couple of pictures with the bell-crank in place with the drag link mounted to the top arm.... The bottom arm is currently about the right height to have a cross-link rod end hanging below, but it can be raised up to an inch (or lowered) by removing or adding the 1/4 inch aluminum  shims above the arm.....

'cross steer', 1 of our off rd mods...

There are a lot of small details to this project that must be right in order to get success, so progress has been painfully slow.....

Full mockup of all moving parts suggests that three inches of suspension drop results in about 5 degrees of bump steer on the steering wheel instead of the about 200 degrees I had (I'll take it!)

This picture shows full right....





Tie rod, cross-link, and stabilizer shock...




This is the tab and clamp that fastens the stabilizer shock to the tie rod

all's fun with 'geometry'.
This just cuz of the 'drop' mod?
Think you're 'there' now or still testing?

I'm in almost $400 in parts and preliminary results show promise...

I still need to complete some bracketry to make sure the bell-crank spindle is rock solid held in place....
I also may re-make the secondary bellcrank arm a half-inch shorter (6") (third version) because it places the tie-rod end only 1/2" behind the tie-rod and that may not be enough space to allow for leaf-spring growth during compression....That would also slow the ratio a bit at the steering wheel (more turns lock2lock)
Right now, I appear to have almost exactly the same number of turns at the steering wheel as original....
I'm pretty sure I'll be without bump-steer though....

I attended the "Havasu Deuces" car show last Saturday that featured mostly pre-war street rods and 99% of those with straight axles had cross-steer...

I got some more pics that hopefully show the setup a little better...





These two views are from behind the left brake drum.....The axle is hanging three inches from where it would be, if loaded..... The hub is right of the leaf spring and could not be fully seen if the axle was loaded..... the cross-link is completely parallel with both the ground and the tie-rod, when loaded....





Additional notes:
All three linkage tubes are matching 7/8" OD x 5/8" threaded ID (L&R threads) in carefully chosen lengths from Speedway... All three are turnbuckle-adjustable with 2 jam nuts each, so all three can be adjusted to maximize travel and centering of both the bell-crank and steering box and for adjusting toe....The four-lug bell-crank hub and spindle are trailer axle parts, complete with tapered roller bearings, a seal and a cap....I will drill in and install a zerk fitting so it will be greasable...Each Arm is fastened to the bell-crank with three 1/2" bolts and height adjustable with 1/4" shims as well as taper-drilled at the ends to accept es350L and es370R tie-rod ends.....The passenger side tie-rod end is inserted through a piggy-back bracket that the cross-link's tie-rod end fastens in to.... The piggy-back bracket is taper-drilled for the cross-link tie-rod end and has a couple of split collar clamps welded inside of it to lock it tightly to the main tie-rod end that is inserted through it....The stabilizer shock end link has a pair of the same style of split-collar clamps (7/8") so it can be loosened to rotate the tie-rod tube to adjust toe.....


In the picture below (taken from the passenger seat area) you can see the bell-crank hub, and if you look above, you can see the spindle sticking up through the blue square-tube structure that it's welded to.... Also shown, is the cross-link and the tie-rod...

Welllllll..... I'm ecstatic to report that all of the pictured assemblies have now been permanently installed and the setup works as I expected it to....

At the end of the "Axle Flip 2.0" thread, I show the plotting the travel distances of the unequal-length bell crank arms.....
In the end I learned that the relative travel distances could be expressed as a mathematical "ratio" by dividing the one length by the other, and could be expressed as a (less than 100%) percentage of distance the shorter arm travels, or an overdrive ratio expressing how much farther than 100% of the small arm's travel that the longer arm travels....

Axle to pin measurements of the two arms are 7.25 inches and 6.5 inches....Sohhh...
7.25" divided by 6.5 inches reveals that the longer arm travels 1.115 inches to produce 1 inch of travel for the shorter arm....
Conversely, 6.5 divided by 7.25 = .896   translates to the short arm having 89.6% of the travel that the longer arm has to provide....

The original scheme was a 1:1 ratio, and I now move the steering wheel 111% of the original distance to get the same turning... (1.115:1)

Designing stuff that fits, still required physical modeling, but the math became an important bellweather of determining if the stuff would have enough reach when finished...

I need to point out that the space needed for the cross steer was available only because I moved the engine rearward 18 inches.....
If you look at the second and third pictures back, you will see a bolt up into the frame to the left of the arm and another bolt hole left of that....These are the threaded holes that the original engine crossmember bolted in to....
Other have found that their tie-rod interferes with the engine crossmember when flipping their axle and have needed to clearance the crossmember.....
I'm not saying that smart people couldn't figure out ways to make my basic design work without moving the engine, but on my van, it would have been impossible, given my skills and chosen materials.....