Better anti wrap ideas?

[Mace]

If you think about it, the only leaf really loaded as a link is the main leaf. The others are not connected at both the middle and the end. The other leaves may offer some support, but it is really up to the main leaf. So it doesn't matter if it is 3 leaf spring or a 37 leaf spring.
If the force vectors are correctly arranged then the loads are balanced and counter-acting. If the force vectors are not correctly arranged then things will break.
It is, unfortunately, a compressive loading. Better would be a tensile loading, but that means that the link has to be a hangy-down part.

The other leaves offer a significant amount of support even more so when we are discussing axle wrap. Heck, just a slightly longer leaf spring pad does a suprising amount of good. The progressivly shorter leaves are increasingly stiff and distribute the forces over a longer area. Plus, they act to push the force further away from the axle. Essentially creating a longer lever arm to combat the rotational forces.

Is Hangy-Down a technical term???

 

[ntsqd]

If the link is correctly located it only sees a tensile loading and the main leaves see a torque reaction induced compressive loading (compressing the leaf down it's length). The other leaves have no part of that compressive load since they are only anchored in one place. All that the other leaves can do is support the main leaf if it tries to buckle under the compressive loading, which may or may not be very effective. If the forward keeper(s) are tight to the main leaf, then a significantly arc'd main leaf (pre-disposed buckling direction) can be backed up by the leaves btwn it and the leaf/leaves that the keeper(s) is/are attached to by the keeper coming in contact with the main leaf though the lent support is only from the keeper back to the center pin

Spring wrap happens when the compressive loading of the main leaf exceeds it's ability to resist buckling. With the thick leaves of the GM's the buckling threshold is considerably higher than with the stock, thinner leaves.



Very technical. It's almost a trade secret and I probably shouldn't have used it.

 

[Mace]

Exactly the leaf springs have to deal with the compressive loading. They are the "second link".
Even a perfectly designed primary link cannot do what it needs to if the secondary link is designed to bend to begin with. It can limit the issues, but with significant stress, it will bend. Different springs/pads etc.. can minimize that bending.. But they will still bend with enough force.

A link that is designed to bend is not a good start.

 

[ntsqd]

No it's not, but a rigid link that is intentionally bending the springs is a worse start.

 

[Mace]

No it's not, but a rigid link that is intentionally bending the springs is a worse start.

Not if it stops you from breaking pinions. And that is the primary reason for doing a wrap bar to begin with. Springs are easily replaceable and do not typicaly fail on the trail. A pinion is not easily replaceable on the trail and does typically fail in the worst spot possible.

And the rigid link does not have to bend springs. The one I had on my 40 could be removed with just about any orientation of the axle. I tried it on a ramp just to see. The forward back movement is compensated with a shackle. The lateral movement is slight, and can easily be taken care of with a big heim or something similar.

 

[CruisinFJ60]

For mock up only.

dont lie we all know your gonna run it on the trail to "test" the design and never remove it.

 

[D'Animal]

I have the Con-Fer fuel tank Mock up done and it is sitting even with the bottom of the frame.

Anybody see a problem with using my extra crossmember as a crossmember for the front mount of the Anti-Wrap bar?



I scored some 1" DOM .120" tubing.

 

[Butt Ugly Chuck]

Anybody see a problem with using my extra crossmember as a crossmember for the front mount of the Anti-Wrap bar?

As long as the geometry seems about right, it makes sense.
Butt

 

[Mace]

1" .120 dom is gonna be on the weak side..

the x member should be fine

 

[D'Animal]

1" .120 dom is gonna be on the weak side..

the x member should be fine

I know but try to find anything else on Sat afternoon or on a Sunday. If I have it delivered during the week they want $20. per foot.

 

[ntsqd]

Sleave it. Use the 1" as the inner, and then find a larger size to be a tight fit over it. Fish-mouth or 'baloney cut' the ends of the sleave for a reduced stress riser.
You'll want more than 1" since that lower tube will be under comprssion (worst case for steel) and has the possibility of hitting rocks/stubs/etc. under load. See my beer can analogy above. K5's have been known to bend 2"x.25" DOM in hard core applications. Not easy and not every time, but enough to warrant caution.

 

[D'Animal]

I picked up the Tube this morning and it was 1 and 1/14 .120 wall.

I didn't get diddley done on the anti wrap bar.

 

[rusty_tlc]

I have the Con-Fer fuel tank Mock up done and it is sitting even with the bottom of the frame.

Anybody see a problem with using my extra crossmember as a crossmember for the front mount of the Anti-Wrap bar?



I scored some 1" DOM .120" tubing.

That tank looks familiar.

BTW .120 is to thin for an antiwrap bar, ask me how I know.

 

[Mace]

Sleave it. Use the 1" as the inner, and then find a larger size to be a tight fit over it. Fish-mouth or 'baloney cut' the ends of the sleave for a reduced stress riser.
You'll want more than 1" since that lower tube will be under comprssion (worst case for steel) and has the possibility of hitting rocks/stubs/etc. under load. See my beer can analogy above. K5's have been known to bend 2"x.25" DOM in hard core applications. Not easy and not every time, but enough to warrant caution.

Very good advice.

 

[Randy88FJ62]

For what it's worth, one of the advantages to the 63" Chevy's touted here on Pirate is you can use the front half of a Chevy overload spring to prevent axle wrap.
Butt

Thanks for the pirate link Chuck. Very informative and enough to get me thinking about using chevy springs in my SOA plans.

 

[ntsqd]

Thanks for the pirate link Chuck. Very informative and enough to get me thinking about using chevy springs in my SOA plans.

I put 63's under the rear of my Xcab, but I used the OE overloads under them. At the advice of a large 4x shop owning friend I put them in upside down as the 63's have a tendency to kink at the front & rear edges of the spring perch. Putting the o/l's in upside down gives the spring a nice ramp to roll down onto. No kinkiness involved.

The Xcab OE o/l's come with a very long keeper at the rear. The idea is that when the spring winds up the cross-bar of the keeper limits out of the top of the main leaf. I would do that b4 I used just the front 1/2 of an o/l or put any sort of snubber on the front of my upside down o/l's. Though with only 4 squirrels and no stupid-low that truck doesn't have that problem until the Marlin goes in.

 

[Randy88FJ62]

I put 63's under the rear of my Xcab, but I used the OE overloads under them. At the advice of a large 4x shop owning friend I put them in upside down as the 63's have a tendency to kink at the front & rear edges of the spring perch. Putting the o/l's in upside down gives the spring a nice ramp to roll down onto. No kinkiness involved.

The Xcab OE o/l's come with a very long keeper at the rear. The idea is that when the spring winds up the cross-bar of the keeper limits out of the top of the main leaf. I would do that b4 I used just the front 1/2 of an o/l or put any sort of snubber on the front of my upside down o/l's. Though with only 4 squirrels and no stupid-low that truck doesn't have that problem until the Marlin goes in.

You lost me a little there. I can almost picture what you're saying but I'm having trouble connecting everything.

 

[ntsqd]

Lost you where?

& how far north of LA?

 

[D'Animal]

I have overloads but they will make the rig too high in the rear.

 

[ntsqd]

Even upside down?