hey guys, started building a single ladder bar set up for my pick up truck.
1950 Chevy 3100
stock frame and leafsprings, lowered 2-3"
ford explorer 8.8" rear end, 3.27 gear, 31 spline axles, 26'' tires
So.... i started with an idea. One ladder bar located close to, or on the center section, with solid axle mounts and a bushed shackle connecting it to the frame. There's a lot of 4x4 guys that use this style set up and the reviews are all pretty good. I looked at some ladder bar set ups and wasn't sure that they were right for me, so i opted to build it myself.
parts:
1-1/4" x .120 wall, DOM steel tubing (12ft)
3/4"-16 chromoly threaded tube ends (x3)
3/4"-16 Comp. Eng. solid threaded ends, with poly sleeve for street (x2)
3/4"-16 Ride Tech. poly bushed end (x1)
leaf spring shackle, stock repl., '98 1500 chevy (comes with hardware and a nice bushing) (x1)
1/4" steel plate for the shackle mount to frame (4x12" plate)
I purchased the parts from Summit Racing, it's good quality stuff. I ordered the big 3/4" ends because i'm using only one bar, and i'm planning adding a supercharger in the future.
The chevy leaf spring shackle has a real nice bushing similar to an A-arm. It also comes with a loose one that, if you planned it correctly, you could press it into a custom tube end. I'll measure the bushing and post it on here. i bought the shackle from O'Reilly Auto.
I dont know how to post pictures into the thread (that'd help the fit-n-finsh) so i'll stop now and post some more.
Bar is adjustable, around 45", 10-1/4" center-to-center at the axle mounts, and consists of two triangles, one circumscribed about the other, with a front gusset at the apex of the tubes.
I welded the bar, as well as everything else in thise post with a TIG welder (Hobart 165i). I thought that would pose some problems, especially on the axle tubes and housing, it actually worked out really well.
165i TIG
3/32" 2%thoriated tungsten, sharpened to point
3/32" Alloy steel filler rod
straight Argon gas
For surface prep i used regular fiber disks and then cleaned it up with a braided wire wheel. The regular grinding wheels can leave little bits of crud in the weld area and they can create some ****ty, porous welds if you hit them. The wire wheel got rid of them. Also, in the questionable spots I used surface cleaner/surface prep for body work (auto parts store).
completed the inner triangle (circumscribed). Everything seems good.
I dont have a tubing notcher so I used the grinder. It took a while and was a PITA, but it all turned out well. The front gusset is 3/16" mild. Welding the tubing should be done in short lengths, about 3" or so to prevent warping and what not.
What I shouldv'e done was make a simple jig to clamp everything to (like a the two far ends clamped to a piece of wood, like a 2x4)..... but, I'm a ******* and the bar move a little. they're still square (amazing) they just got close together. No worries, it actually worked out better.
Started making the axle mounts. I used 3/16" angle steel and 3/4" bolts. The nonhardened stuff is for mock up, I couldn't find the right shoulder (grip) length in grade 8 stuff, so grade 2 will suffice for now.
The axle side end links have a nice poly sleeve in them. Comp. Eng. sells these for street use.
I have to finish the lower mount, the upper is done. I'm not entirely convinced that i need a rear gusset on the axle mounts. If i decide to do it I'm going to use 3/16" plate.
Everything seems to be going well. I should be finishing up with the whole thing this week. I've put a lot of thought into this, and spent a good deal of time sourcing realiable street parts, so I'm hoping for good results. I have the part numbers and prices for those interested. I blueprinted this set up for that reason.
i was concerned about welding the axle housing with the TIG. I've read some stuff and it seems hit or miss.
I'm using the Ford 8.8" from a '94 Explorer. From what I've found these units are steel instead of cast iron or something... either way, they weld nicely! I was super pumped to find that. Again, some good info from the 4x4 dudes.
I'm close to wrapping this up. Figured I'd post something that i hope you guys find useful. I've gotten a lot of information from here and i really dont want this to be 'status quo'. If you have questions or comments, I'd like to see them.
I'll post the finished lower mount, and driving results when I'm done.
got the lower mount done. it was a PITA. I found some hot cracks (+1000*F, appear instantly) in a few spots and some cold cracks showed up (-1000*F, takes a few days). I figured this may happen. on the upper mount I only had cold cracks, on the lower there's some little hot ones. i'm going to grind those out and use the MIG on a lower amperage in order to avoid excess heating. I f'd that one up and I didn't want to leave it out of the post. figured someone could learn from it or some old timer can make fun of me... either way.
other than some cracks, it's lookin good. no road test yet as it started raining LITERALLY as soon as I finished bolting stuff together. i'll post the results I from the road test. hopefully it'll be positive.
Nice looking fab work, Ben. If I could make a few observations?
1.) The leaf springs are still there, right?
2.) The panhard bar is very short. The bar will push the axle back and forth, crosscar, in an arc not in agreement with the "straight" up and down travel of the leaf springs. This will put a lot of deflection (read as "bind") into the leaf spring bushings.
3.) The panhard bar is at an angle at ride height. This angle will induce more "arc travel" of the rear end into jounce then rebound. You really want the bar parallel to the ground at ride.
4.) The ladder bar front mount is farther forward, in the side view, then the leaf spring front bushings. This will also drive more bind into the leaf spring mounts as the rearend will now want to rotate around the ladder bar front mount as well as the leaf spring mounts.
I do not want to get you upset... Suspension design is what I do for a living so I notice things like this...
Mark
Mark,
Yes the leaf springs are still there. I know the bar is short and angled down somewhat. Two things: 1) the axle does move side to side. It has rubber bushings and stock shackles. It moved just as much, if not more than the panhard will move it. 2) were the bar to be level, upon compression at current bar length it would deflect the axle laterally the maximum amount possible. Presently, It starts midway through the arc, and upon compression of the springs the bar should only make it back to the opposite midpoint. Theoretically, this reduces over all axle displacement because the panhard bar arc length is reduced.
Regarding the front mount: I have a large leaf spring shackle that the bar connects to. It will move fore and aft (and yaw somewhat because there are two rubber bushings on the ends). Yes the bar and the leaf spring have disimilar arc lengths, however the shackle should compensate for this, at least that was my intention. We're it to be rigidly mounted to the frame at the front, I should think it would bind.
Now, as a suspension guy, do you still think it would matter that the arc length of the leaf spring and ladder bar are different, even though the bar is able to move front-to-back with the axle?
You won't upset me. That's why I post this stuff. I want to know what you guys think.
Hmm. I can see what you were thinking when you designed the front mount. I am wondering how effective it will be to control axle wrap. As loose as it is I really doubt it will have much of a controlling effect on pinion lift at launch.
It won't cause any bushing bind in the leaf springs because it will just saw back and forth on the shackle during jounce and rebound.
I will be very interested to hear how it works out. I would really like to see a go-pro vid of it in action.
Keep us in the loop on this please.
Mark
Mark, ill definitely keep you in the loop.
My thought with axle wrap was this: the axle body will rotate about the axles center line causing the pinion to climb. The top of the housing will rotate rearward while the bottom is 'pushed' forward. The upper and lower ladder bar mounts on the axle should control this movement and in turn cause a lifting effect at the front of the bar that is mounted to the frame. Now, because of the softer bushings at all bar mounts, and the shackle in front, the bar will inherently allow some movement and thus, not completely resist axle wrap. However, it can only move so far along all of the stressed axes, and ultimately it will control the axles wrapping. It's effectiveness will most likely be on a graduated scale rather than a pass/fail. So, in theory I've combined a ladder bar and a lift bar. There should be lift created at the front of the bar, and the axles propensity for rotation should be mostly controlled between the upper and lower bars on the ladder.
i did something similar on my 58 truk w/ stock springs and flipped axle
after i had truk on the road i experienced a lot of axle wrap that caused the driveshaft to rub a x-member on a hard take off
luckily i had used a 2nd gen trans am that came with a torsion bar boss on the rearend housing
i bolted the stock 82-92 torsion bar on the housing, cut the front mount off and used a trailer shackle at my trans x-member
the torsion bar and the leaf springs have different pivot points, the added shackle makes a variable pivot point up front
works great
on leaf springs i'd remove the panhard bar as it will counter act and bind with the leaf springs
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