• Welcome to ClassicBroncos! - You are currently viewing the forums as a GUEST. To take advantage of all the site features, please take a moment to register. It's fast, simple and absolutely free. So please join our community today!
    If you have problems registering or can't log into your account, please contact Admin.

Dan Wheeler's Anti-Wrap Bar Build/Install/Review Thread

DanWheeler

Bronco Guru
Joined
Nov 8, 2005
Messages
2,549
Loc.
Kirkland, WA
With the recent upgrade to 41s, 5.38 gears and leaving the rear axle on leaf springs, (for now) I've noticed an increase in axle wrap which is causing the front end to jump up when I take off from a stop.

I did a little research on the subject and settled on an anti-wrap kit from Ruff Stuff Specialties. (www.ruffstuffspecialties.com) They have recently added a "complete kit" to their lineup which includes (almost) everything you need to build a anti-wrap bar including the DOM and heim for a very reasonable price.

here's the link to the kit:
http://www.ruffstuffspecialties.com/catalog/AWKIT.html

antiwrap%20kit%20no%20tube.jpg


The picture is missing a few pieces that I expect to be included in the kit. I should find out Friday when it arrives. I am expecting it to have everything needed except for a way to mount it to the frame:

- The brackets that attach to the axle
- The 2 bushings and hardware on the axle side
- The DOM
- The heim on the frame side
- The shackle and bushings on the frame side

It says in the parts list that it includes (1) 2-5/8ths bushed DOM sleeve which should fit into some leftover Ballistic frame link brackets I have from my last project. I dont plan on building a cross-member for it, which I will get into later.

here are 2 discussions about anti-wrap bars on Pirate:
http://www.pirate4x4.com/forum/showthread.php?t=991070
http://www.pirate4x4.com/forum/showthread.php?t=351224

Basically what I gleaned from the above reading is:
- Your front mount should be as low as possible. Just like a link suspension, lower and flatter will give you better antisquat numbers.
- Put the antiwrap bar on the passenger side (if possible - but not critical) to combat the natural torque-roll from the motor
- Make it as long as possible (again, same concepts as link suspension)
- Put the shackle in tension (during forward acceleration) if possible

so with that in mind, I plan on mounting my ballistic frame link mounts directly under my frame (just like my front 3-link but pointing backwards) and attaching the shackle to that. With 41s, I'm not very concerned about ground clearance, and it shouldn't hang down any further than my front 3-link mounts. The shackle will be in compression (not tension) on forward acceleration but that is a sacrifice I will have to make based on space constraints.

here's a good example of what I think is a properly built/designed (geometry-wise) anti-wrap bar:
MVC_832S.jpg


...to be continued this weekend.
 

hartbronco

Sr. Member
Joined
Aug 9, 2007
Messages
428
Loc.
Powell River B.C Can
Hey Dan I was just looking at doing this as Myself ..... it seems that my pinion is moving around 6" up and down ( give or take ) on just the street with not much load on it . As far as on the trail I seem to loose traction because of the axle wrap . I was going to order a kit ( this week ) as well But I think I will hold off untill You up date this .
Thanks for Posting .
Darren
 

Slim

Jr. Member
Joined
Apr 12, 2010
Messages
119
Loc.
Costa Mesa
I don't have one, because of no axle wrap but from what I have read is that:

The shackle should be in tension which would put the traction bar itself on top part of the shackle and the mounting point below when installed. Also, that the traction bar should be as close to parallel with the drive shaft as possible. And, that the mount on the axle tube should be as close to the center section/pumpkin as possible. All this will give you the best articulation. Maybe you are not after articulation so may not be a big deal but if you are going to do it may as well do it right from the get-go.

Interested to see howmit works without the cross member application. Good luck and post pics of the install/fab.
 

Nightstick

Bronco guy
Joined
Feb 6, 2010
Messages
2,929
I'll add THIS ARTICLE to the thread. Does a good job of explaining axle wrap and what to do to prevent it. I'm gonna need to put one on my trail rig sometime in the not so distant future.
 

KyleQ

Bronco Guru
Joined
Apr 24, 2008
Messages
5,480
Bad ass - this is exactly what I've been planning on doing. Looking forward to the updates!
 

ryan287

Full Member
Joined
Jan 15, 2006
Messages
190
Loc.
Orange County, CA
I had the same problem with axle wrap and went through many U-joints as a result. I made mine in my garage using some Heim joints and a "Johnny Joint" from Currie Gear in front. The cross bar doesn't go any lower than the the one for the transfer case. I haven't worn out any U-joints since (a few years), but I did twist off my transfer case output shaft drag racing.

http://classicbroncos.com/photos/showphoto.php/photo/14897/cat/500/ppuser/14760
 

Bronchole

Bronco Guru
Joined
Mar 24, 2004
Messages
1,611
Loc.
Chatsworth, Ca (LA)
I almost went this exact way with mine, but I ended up making something more simmilar to the Wrap Trap . Still I think the "Sam's" bar design is a viable solition. I especially like that it doesn't use the leaf spring as part of the linkage. That is the main downside to the Wrap Trap design.
 
OP
OP
DanWheeler

DanWheeler

Bronco Guru
Joined
Nov 8, 2005
Messages
2,549
Loc.
Kirkland, WA
Maybe you are not after articulation so may not be a big deal but if you are going to do it may as well do it right from the get-go.

Maintaining the excellent articulation of the leaf springs is definitely a must here. As far as I can tell, the anti-wrap bar should not limit travel.

- It allows front to back movement because of the shackle
- It allows the axle to rotate on the axis of the driveshaft because of the heim
- It allows side to side movement because of the bushings and the heim (even though it is the job of the leafs to prevent it)

Unless I'm missing something, the only thing it should prevent is axle rotation on the axis of the axle shafts. I'm hoping so anyway - I will find out soon.
 

Bronchole

Bronco Guru
Joined
Mar 24, 2004
Messages
1,611
Loc.
Chatsworth, Ca (LA)
I think that much of the observations about this type of traction bar (as well as the type I went with) limiting the travel have more to do with them not being adjusted/constructed correctly than the design itself. In the design that Dan Wheeler is going with you want to have it set up so there is minimal bind when the suspension is at or very near full drop. This will load the arm a bit at normal ride height because it will be attempting to change the pinion angle so that its angular relationship is constant to the forward pivot point of th arm. Since the bind is happening at a point in the travel where the suspension is already pretty well loaded I doubt it would even be possible to measure.

Most of this is just my hypothisys, but the little bit of research I did makes me confident enough in this that I don't mind sharing.

The one thing that made me flop camps from using the Sam's type design to the Wrap Trap type design was when someone pointed out that if you cycle you suspension from as compressed as you can get it to unloaded that the pinion angle to the ground does not chnage substantionally. I actually went out in to the driveway to verify this, its true! This means that when the Sam's style traction bar is installed that at some point in the travel the traction bar must actually load itself against the leaf springs to rotate the axle housing. Probably not much of a load, but another load that the traction bar has to deal with.
 

KyleQ

Bronco Guru
Joined
Apr 24, 2008
Messages
5,480
This design will not limit travel in any way - this is the best setup available, better then running a slip/slide style.
 
OP
OP
DanWheeler

DanWheeler

Bronco Guru
Joined
Nov 8, 2005
Messages
2,549
Loc.
Kirkland, WA
Dam Dan, I just noticed the articulation you are getting on the front suspension in your avatar.

:cool:

and the rear is exactly opposite angle in that pic and the body is about as level as it could be. The coilovers weren't even fully stretched yet.

SANY0006-M.jpg


SANY0007-M.jpg
 

Bronchole

Bronco Guru
Joined
Mar 24, 2004
Messages
1,611
Loc.
Chatsworth, Ca (LA)
Now you are just showing off ;)

Someday I hope to get my junk up to Washington and wheel a bit with you. Even though our builds have taken very differnt ways I love reading thru yours to see what ideas are out there.
 
OP
OP
DanWheeler

DanWheeler

Bronco Guru
Joined
Nov 8, 2005
Messages
2,549
Loc.
Kirkland, WA
ok - here we go. Got parts in the mail today and started building the antiwrap bar. It's going pretty well but I've had a few slowdowns.

1) the brackets were not for a 3.5" diameter axle so I had to modify them with the grinder
2) The frame side of the shackle is drilled for 1/2" but a 9/16ths bolt and bushing is provided and I dont have a 9/16ths drill bit.
3) I welded my brackets too close to each other and had to pull one side off and re-weld it.
4) the top gusset bolt head or nut conflicts with my spring plate

as you can see, the closest location to the diff on my axle tube puts the antiwrap bar directly under the frame which is convenient because thats where I'll hang my shackle.

Photo3F8EC10F-7840-8F96-A82C-M.jpg


I'm finding that the order in which you assemble the antiwrap components is very important. Here's what I would recommend:

1) Assemble and tack weld the axle side DOM sleeves and moon-shaped gussets on a flat surface. I decided to locate the moon-shaped gussets about 1/8th from the edge of the DOM bushing sleeve to give me some room to weld both sides of the gusset to the DOM sleeve without ruining the edge of the DOM sleeve. If you do this, put some 1/8th inch plate on the floor under the gusset to provide even spacing. Otherwise just lay it all flat on the ground, tack it, turn it over and tack the other gusset. This gave me some trouble later because with the gussets so close to each other, the main 2" DOM tube doesn't fit between them. I had to get creative with the cutting wheel but it worked fine.

2) now that you've tacked the gusset piece, you can insert the bushings and internal sleeve and not risk burning them up with the welder.

3) attach the main brackets to the gusset piece, insert the bolts plus one thin washer on the inside to give a little extra space between the main brackets. This will ensure you can still fit the gusset piece and bushings after welding the main brackets. You can always crank down the bolts/nuts to fill a 1/6th inch gap but its much harder to jam a bushing into somewhere too small.

WP000075-M.jpg


4) Make sure the main brackets are parallel, level, even, where you want them, etc and tack weld them.

5) fishmouth your DOM tube to fit the DOM sleeve. Notch it if necessary to fit between the moon gussets.

WP000081-M.jpg


6) locate/weld your shackle hanger wherever it needs to go. In my case, I'm just going to weld the DOM sleeve directly to the bottom of the frame:

WP000078-M.jpg


7) install the shackle and heim joint with the threaded insert and nut threaded onto the heim where you want it (provide a little room for adjustment while maintaining a good amount of thread engagement)

8) set the shackle angle how you want it. I'm not going to provide any guidance here because I dont actually know what I'm doing. I set mine roughly perpendicular to my lower bar.

9) Now measure from the bottom DOM sleeve on the half-moon gusset to the lip on the threaded DOM insert. This is how long your DOM tube should be. (make sure you account for the fishmouth when measuring)

10) With the vehicle at normal ride height, set the DOM onto the lower DOM sleeve and insert the other side into the threaded insert on your heim/shackle combo and tack weld it to the DOM sleeve. Do several tack welds because the weight of the DOM will be putting a lot of leverage on the tack welds.

now you should have something like this: (upside-down in this pic)
WP000083-M.jpg


11) remove the bushings and burn everything in

WP000085-M.jpg


Thats as far as I got but I think the rest will be very simple. The most difficult part is setting up the main brackets and half-moon gussets. Things move around from the heat of the welder and the half-moon gussets and main brackets need to be perfect. If you get those wrong, you will have a hell of a time lining everything up and putting the bolts through.

I should have some more pictures tomorrow and maybe even a test drive
 
OP
OP
DanWheeler

DanWheeler

Bronco Guru
Joined
Nov 8, 2005
Messages
2,549
Loc.
Kirkland, WA
Finished up the anti-wrap bar tonight minus the final painting and wow, what a huge difference! I had been too afraid to floor it from a stop because I was worried about wrapping the springs but now I can stomp on it and the Bronco stays level but the hole truck seems to lift up a little bit. Its a really interesting feeling I can't describe but I think its a good thing. It really feels like the tires are digging in.

I ran into a few issues towards the end of the installation:

1) upper bracket bolt head conflicts with spring plate. Had to notch the spring plate and now I have to remove the spring plate and leaf spring if I want remove the upper bracket bolt to remove the antiwrap bar.

2) my shackle angle is wrong. I moved my shackle mount back and ended up overcorrecting.

3) The weld on the diff side of the bracket cracked while cranking down the bracket bolts. I'm just going to have to hope 3 out of 4 sides of the brackets is good enough. I knew I was in trouble when my tack weld on the diff side of the bracket sizzled, snapped, and popped and then cracked right away. I preheated a 3" section to 350 degrees and laid down a weld which immediately cracked. I pre-heated again and got a good weld that didn't crack right away so I started peening it and doing a slow cool down, applying heat every 30 seconds or whenever it started crackling. I did this on my front Dana 60 truss and it takes a lot of patience but worked well in that case. To make a long story short, when I went to crank down the bolts for the antiwrap bar, I heard a crack and that was the end of my weld to the diff. :( :( :(

4) the shackle/heim bolt is too short and does not make contact with the nylock part of the nut.

5) it took FOREVER to notch the upper bar to fit the lower. I'm not sure the upper really needs to be quarter inch. It would make notching it a lot easier if it were thinner wall.

I plan on updating the instructions on the first post to be more clear but here are a bunch of pictures.

Overall, I'm VERY happy with the kit for the money. Plan on spending about 10-12 hours or maybe less if you can avoid some of the issues I ran into.

WP000090-M.jpg


WP000091-M.jpg


WP000093-M.jpg


WP000095-M.jpg


WP000103-M.jpg


notice the crack in this pic
WP000098-L.jpg


welding to nodular iron takes lots of preheat, peening and patience
WP000100-M.jpg


WP000102-M.jpg


shackle is leaning too far back:
WP000110-M.jpg


I removed all my leaf spring bushings to lube them up and re-enforced the shackles while they were out
WP000104-M.jpg


notching the spring plate
WP000107-M.jpg


WP000112-M.jpg


WP000109-M.jpg


WP000111-M.jpg


WP000116-M.jpg


WP000115-M.jpg
 
OP
OP
DanWheeler

DanWheeler

Bronco Guru
Joined
Nov 8, 2005
Messages
2,549
Loc.
Kirkland, WA
also... this design DOES cause bind. In theory, leaf springs pivot on the non-shackle end but in reality they seem to have more of a linear movement up and down.

The antiwrap bar on the other hand pivots on the heim bolt absolutely. So with this design we are mixing quasi-pivoting leaf springs with absolutely pivoting antiwrap bar.

For example, if I remove the antiwrap bar shackle, support the frame with jackstands, remove the wheels/tires and lower the axle 2-3" with the floor jack, the frame-end of the antiwrap bar will be roughly 2-3" below the shackle.

Due to the nature of leaf springs and their ability to "wrap", it all seems to work out OK but there IS bind in this system. I was able to lower the axle to the ground quite a ways and the antiwrap bar was not preventing it from going further. In reality, the center section would never drop down that low and because the anti-wrap bar attaches close to the center section it should see a minimum of up/down movement as the axle articulates.
 

Ranchtruck

Sr. Member
Joined
Feb 7, 2008
Messages
766
It may actually produce less bind in the suspension when under use. The springs are asked to do three tasks; support the weight of the vehicle, control the position of the axle, and transmit the twisting force of the axle to the frame.

The anti-wrap bar takes over the last task, and it does a better job of it than the flexible-by-design springs do.

The springs themselves are normally put in bind by the twisting of the axle from driving force. Take that away from them, and the leaves will no longer be jammed against each other on the leading end so the sliding friction against each other should be much less. You also reduce the jacking effect that torque twisted springs give. That should reduce the effective spring rate leading to more flex.
 

Bronco73

Bronco Guru
Joined
May 29, 2003
Messages
2,989
Loc.
Cape Coral, FL
I'm not sure the weld on the frame piece will hold up. Do you think adding an extra brace on both sides of the tube welded to the frame would be better? It just seems like a lot of load is placed on a small amount of weld.
 
Top