Front axle hill-climb limiting strap

[arrabil]

I can't remember who here put a limiting strap on their front axle [probably 4x4junkie :)] but can they post some pictures and/or explain what they did? I don't understand how it prevents uphill front-end lift without limiting down travel when you want it.

[JohnnyU]

If you were to get creative, and mount a pulley on the outside corner of both sides of the frame, and used a fixed length of cable, that would still allow your suspension to travel over terrain, but it would prevent both sides from dropping out together.

[4x4junkie]

Yep, thats what I did on mine. The cable has just enough slack to let the tires droop together about 3-4" from ride height. This is so the onroad ride isn't affected.

You can see the cable in this pic, I'll try to get more pics of the 1x1 sq. tube I used to run the cable through.

http://memimage.cardomain.com/member_images/6/web/702000-702999/702959_47_full.jpg

[arrabil]

4x4junkie, the underside of your BII is just plain wrong. I was just admiring the neighbor's BII because its only starting to get cancer unlike mine which is end-stage. All I have to look forward to is global warming I guess. And then everyone from Cali will move north because it will be too hot.

Anyway, between JohnnyU's repsonse and that picture, I completely get it. Thats pretty smart. I was climbing the right-of-way on my property and the nose lift was just unbearable. I don't have rear shocks on right now so that doesn't help but I could feel the scissoring effect pretty good.

[4x4junkie]

Lol, that thing's not quite as 'perfect' as you'd expect a Ca vehicle to be, the core support has a bit of rot around the bodymounts, and when I pulled the rear shock brackets off to extend them, there were layers of rust flaking off both the frame and bracket in between there (I think it may have spent at least one or two winters back east maybe)


You got your springs in?

[arrabil]

Lol, that thing's not quite as 'perfect' as you'd expect
Sigh. :o

You got your springs in?
I was taking a final spin in the current configuration to remind myself what it feels like off-road so no, and I haven't gotten the Heep isolators in the mail yet. That and my wife reminded me (thats the nice way of saying it) that I promised to finish the kid's swingset and start his treehouse before I worked on the BII anymore. So, the swingset is done minus a few loads of dirt to level out the ground and the tree brackets are gonna get welded Wednesday if I don't get called away to work. My wife chose a 20x24' treehouse design that will attach to four trees!!! And the trees need to move with the wind without ripping the tree house apart so I've been learning all about treehouse supports that allow for that. Life is entirely too busy and complicated. I hope my boy likes building things and helps me out in a few years.

[4x4junkie]

Dang! That's some treehouse project you got going. Your boy is gonna have it made in that thing.:rockon:


Anyway, here's some more pics:

http://memimage.cardomain.com/member_images/6/web/702000-702999/702959_50.jpg (http://memimage.cardomain.com/member_images/6/web/702000-702999/702959_50_full.jpg)http://memimage.cardomain.com/member_images/6/web/702000-702999/702959_51.jpg (http://memimage.cardomain.com/member_images/6/web/702000-702999/702959_51_full.jpg)

Pulley
http://memimage.cardomain.com/member_images/6/web/702000-702999/702959_52.jpg (http://memimage.cardomain.com/member_images/6/web/702000-702999/702959_52_full.jpg)

I just welded the 1x1" tube straight to a couple of common 2½" hardware-store pulleys. Just make sure they have metal wheels (not plastic)
(the ones I have say National on them)
The cable is 3/16" stainless I got at the same hardware store (I've seen this at Home Depot as well).
The brace on the side adds lateral stability to the whole thing.

[arrabil]

When I get the treehouse platform done I'll post some pics. Its what happens when you give the woman a book of designs and say, "Pick whichever one you want." His daycare teachers and friends have already volunteered us for next years summer party.
----
What you did is totally awesome! I've been sitting here for five mintues, repeating to my wife, "That is just fawking genius right there." [Don't get too big a head though. :)] I think I may add this to my short list of projects to do before I get The Deuce back on the road.

Do you realize the 1x1 tube is rustier than the truck? Talk about irony.

I take it you don't get ANY flak for having a Ford on the trails full of Heeps, huh? Make some stickers that say, "I've been schooled by a Bronco II" and refuse to courier parts unless they stick it somewhere prominent.

[4x4junkie]

I actually came up with this after seeing a dude that had something similar on his lifted TJ. His was a strap going from the center of the axle (straightaxle) to a crossmember on the frame, which effectively served the same purpose.
It definitely makes a big difference in stability. You don't have the front suspension unloading near as much (raising your CG and throwing all the weight on the rear axle). You'll have better visibility over your hood, too.


As for getting flak from Jeep owners... happens all the time. I just ignore 'em and remember why it is I won't ever own a Jeep :no2:
That's a cool idea on the sticker thing though (There's been more than a couple occasions I've had to ferry Jeep parts, too lol).


Its what happens when you give the woman a book of designs and say, "Pick whichever one you want."
*****************

Asterisks... *** Gotta have them asterisks when you make offers like that lol.

[arrabil]

I've seen the center limiting straps for straight axles. This is much more ingenious than that regardless of what inspired it.

I got my Prothane isolators today. They don't really "hold" the spring. I'm gonna drive out to the Jeep dealer and compare it to the stock isolator. I'll have my 3/4" spacer already then. f'n well-laid plans.

[4x4junkie]

I've seen the center limiting straps for straight axles. This is much more ingenious than that regardless of what inspired it.


Yeah, I guess it is a little bit simpler to do this on a straightaxle than a TTB, huh... :icon_twisted:

I like it though. Watching the faces of people like that turn puzzled when I come up behind and plant the tire of my "crappy" bronco II with it's "IFS" junk on the same rock they just got done teetering over makes it all worth it. :D

I think it was only around $20 or so for the parts needed to make it anyway.

While mounting it, you might have to trim the corner of your battery tray just a bit to get it to clear. It shouldn't interfere with the battery itself at all though.

[arrabil]

Yeah, I guess it is a little bit simpler to do this on a straightaxle than a TTB, huh... :icon_twisted:
Not even close.

I like it though. Watching the faces of people like that turn puzzled when I come up behind and plant the tire of my "crappy" bronco II with it's "IFS" junk on the same rock they just got done teetering over makes it all worth it. :D
:taunt:

[PARKINGLOT]

so, are they pullies welded in place and don't move, the cable only slides on them?

it looks like you mounted the cable on the front of the beam where the sway bar would have attached...it that it? got any pics of how you mounted it?

[Bent Bolt]

I am missing the point here. What is the purpose of the straps and doesn't it limit flex ????

[Sasquatch_Ryda]

The cable doesn't let both front tires go to full droop at the same time when climbing hills, helps keep the nose down and the front tires on the ground. But it still lets one side droop and the other stuff so it doesn't limit your flex at all.

[4x4junkie]

so, are they pullies welded in place and don't move, the cable only slides on them?


Notice the pulley's axle pin and clip sitting on top of the tube there. That's what they rotate on ;)

The cable is simply wrapped around the swaybar bolt on the axle, and secured with two cable clamps.

I am missing the point here. What is the purpose of the straps and doesn't it limit flex ????

When climbing a steep hill or any obstacle that points the hood of the truck upward (especially on a short-wheelbase rig like a BII, or jeep), weight transfer carries much of the vehicle's weight onto the rear (or downhill) axle. This causes the front suspension to unload (extend out), further raising the hood and throwing even more weight onto the rear. The better you can keep the front axle down (and keeping more weight on it), the better your stability and overall traction will be.
In the case of a TTB with the notoriously crappy steering you get with a mis-matched pitman arm, the suspension's unloading becomes compounded by the tires toe-ing in at the same time. A limit strap or cable would certainly help some with this as well.

Flex is not limited in any way. As one side moves up, the other side is allowed to move down.

[JFA_Spyderman]

Yo,
Does this compare with an actual sway bar on the road at all? By the looks of it, i am guessing no because there is no way for the cable to push back. Is that right?
Thanks!

[4x4junkie]

No, this doesn't substitute for a swaybar, it doesn't affect onroad handling vs. no swaybar at all.
If you set the slack real tight, it's possible you might feel it pulling against the axle when going over speed humps or through crowned intersections, though.

[BDAB]

this is the most genius thing I have ever seen. you need to do a right up on it and submit it for the tech library.

[4x4junkie]

this is the most genius thing I have ever seen. you need to do a right up on it and submit it for the tech library.

Hmmm. I wouldn't have thought there'd be this much interest in this, I guess I'll have to get to work on it then :huh:

[PARKINGLOT]

one more great idea from the mind of junkie!

[Bent Bolt]

Cool idea. Thanks.

[CopyKat]

Interesting idea.

[samsonitesamsonite]

as soon as I get some tubing, Im gonna do it.

[CopyKat]

But it looks soo kool!

http://i128.photobucket.com/albums/p198/Villanmotorsports/BIV%20Bronco/MoreBIV323.jpg

[CopyKat]

Now I got to thinking. How do you keep the cable in the pulley? what happens to the slack in the cable?

Now if you were to add a nice heavy spring between the cable ends. you could use it to pull the slack but the spring will allow some slack in the cable.

Ideas are floating now.

[arrabil]

I was thinking that too, but it seems to me the cable has no where to go put the pulley groove when it gets tensioned.

[CopyKat]

So Junkie how much droop did you limit it too?

I still think it's alot of snapping and chaffing having the cable slack like that.

[arrabil]

So what rate spring would you use and rated for what strength? They have to hold a serious amount of "bouncing" weight. 4x4junkie said he has 3-4" slack for each wheel.

[kunar]

So what rate spring would you use and rated for what strength? They have to hold a serious amount of "bouncing" weight. 4x4junkie said he has 3-4" slack for each wheel.

i was thinking about this at work today, you dont want a spring inline in the cable. what you need is a pulley somewhere in the middle of the cable where it is slack that is pulled out by a spring. that way the tension from the cable never travels through the spring. anybody understand what i'm saying? it will work like an idler pulley, it has to be inline with the other pulleys though. i have also seen somewhere (magazine im sure but i dont remember where) that people had used small atv winches attached to the frame to pull on the axle, compressing the suspension. this could also be adapted to the ttb, my first thought would be by mounting the winch to one axle beam in the same spot where the cable would normally be teathered. with this setup the axle could still articulate but the length of cable could be changed...if you really want to get technical you could use one winch for each side so you could adjust them individually....

edit: if you wanted a spring inline, it would have to be similar to a screen door chain's spring, set up so after it is extended a certain distance then be mechanically limited, another idea would be putting a couple loops in the cable maybe 8" apart and putting a 4" spring between them so the spring can only stretch another 4" before the cable is taught but now im just rambling...

[4x4junkie]

Now I got to thinking. How do you keep the cable in the pulley? what happens to the slack in the cable?

Now if you were to add a nice heavy spring between the cable ends. you could use it to pull the slack but the spring will allow some slack in the cable.

Ideas are floating now.

The cable is completely contained within the tubing, it has no place to go but the pulley groove when it pulls tight.

The slack isn't a problem either, it's hardly different than the slack you'd have with any other limit strap, just make sure it won't get caught in or on anything (unlike a nylon strap, you can also "bend" the cable slightly so it hangs away from things like the coil spring, etc. too).