Interlocking Tube Couplers

YJJPWrangler

YJJPWrangler

Well-Known Member
Joined
Jul 19, 2005
Location
Charlotte
I am planning on building a rear cross member for the Willys that the traction bar will attach to. I'm planning on attaching the rear crossmember to the transfer case cross member. I want to use something like this

1-3/4" Interlocking Tube Coupling

in between the two crossmembers. The reason I am doing this is I want to be able to remove the transfer case crossmember for maintenance etc but do not want to go through the hassle of removing the traction bar as well. My question is are these tube couplers designed for this kind of use? I know they are used for cages/exos etc but I am concerned about their longevity(Barnes or otherwise) with the constant movement of the traction bar.

See the crude paint sketch. The red boxes would be the tubing couplers that would span between the two crossmembers.


 
I have them on a crossbar through my cage, the seats used to mount to it. You have to pull that bar to remove trans. As long as they are tight there is no movement, the ones i have actually have a slight interference fit. I dont know the manufacturer due to them being there upon initial purchase.
 
Are you talking about a track bar or a traction bar? Oh, that's a top view drawing, so traction bar. Looked like a single track bar mount for a second there.

If you're making a crossmember, why not make the crossmember unbolt at it's mounts instead of making a single piece of the crossmember removable?
 
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^^ the crossmember bolts to the frame but holds up the trans so I'm sure Zack doesn't want to deal with that if he can design around it now.

I would think the couplers would work well so long as they are orientated so that they just use the bolts to keep them together and not taking the brunt of the major forces.
 
It is for a traction bar since I am SOA in the rear. I agree that the traction bar x member will bear the majority of the load. I wanted to add the vertical bars between the two cross members so that there would be stiffness in the horizontal plane(for both cross-members).

Right now the transfer case crossmember can unbolt at the frame and be removed. The traction bar x-member will need to be welded to the frame. Bottom line, I was thinking that constant loading/unloading of the rear axle under acceleration/braking could potentially have a negative effect on a tubing coupler. From the responses, I shouldn't worry about it as long as everything is properly braced and supported.
 
Fabrik8 said:
...
Click to expand...

This.

And why do the cross members need to be attached to each other? If you feel they do need to be connected, why not just connect them with a bolt on skid plate? (Assuming you will have a skid plate.) This is similar to the way my cross members are connected.
 


This is my current transfer case crossmember. The traction bar x member will be behind this one on the frame. The transfer case cross member needs to be removal. The traction bar x-member does not need to be removal. I feel that I need to add bracing in between the two cross members to brace one another for two reasons. 1. The constant loading/unloading of the traction bar will put stress on the traction bar cross member in the X plane. 2. I plan on adding a hoop to the front transfer x member to protect the transmission. I don't want to slam the transfer case crossmember into a rock etc and have it be pushed backwards.

Those are the reasons that I think I need to tie the two x-members together.
 
Brace/triangulate the traction bar crossmember properly to the frame instead of to the transfer case crossmember. That transfer case crossmember isn't meant for transverse loading, so why use it as a brace for something that mostly sees transverse loading? You just need to make it stiff in bending, which can be done without tying it to the other crossmember which is is also not stiff in bending.

Btw, what is the X plane? X is not a plane, do you mean X axis or do you mean the XY plane (horizontal plane in SAE coordinate system)? XY plane I assume.. the traction bar crossmember will see bending loads in both X and Z axis unless your traction bars are only horizontal.
 
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I have a centered traction bar and bent the .120 wall tubing it's made of. I went back and put cross braces above it. If you are worried about it flexing can you tie it into your cage right above where it mounts to the traction bar?
 
Fabrik8 said:
Brace/triangulate the traction bar crossmember properly to the frame instead of to the transfer case crossmember. That transfer case crossmember isn't meant for transverse loading, so why use it as a brace for something that mostly sees transverse loading? You just need to make it stiff in bending, which can be done without tying it to the other crossmember which is is also not stiff in bending.

Btw, what is the X plane? X is not a plane, do you mean X axis or do you mean the XY plane (horizontal plane in SAE coordinate system)? XY plane I assume.. the traction bar crossmember will see bending loads in both X and Z axis unless your traction bars are only horizontal.
Click to expand...

Sorry, I meant it as XY Plane. I realize that the traction bar crossmember will also see loads in the Z axis as well. Thats a good idea on tying the traction bar x member to the frame. I think that can be done quite easily. And it will offer more stability under bending loads as well. With that being said, do you think there is any benefit to tying the two crossmembers together? I still want to add a hoop to the front transfer case cross member to protect the transmission. I could bolt the hoop to either side of the frame as well.

I'm just trying to think of ways to reinforce the frame. These frames aren't the strongest and have been known to twist in some situations. The addition of these crossmembers and the cage in the future can help prevent that.

ghost said:
I have a centered traction bar and bent the .120 wall tubing it's made of. I went back and put cross braces above it. If you are worried about it flexing can you tie it into your cage right above where it mounts to the traction bar?
Click to expand...

Got any pictures of the cross bracing above the traction bar? I was planning on using Barnes traction bar kit. I do not have a cage right now but will be adding one in the future.
 
I don't think theres any benefit to tying them together, no. The transfer case crossmember is only a support member, and that's all it needs to be. Keep them separate and simple, there's no need to reduce serviceability when there are elegant solutions without any compromises related to the transfer case maintenance.
 
I feel like a connection via sleeving one DOM tube into a larger DOM tube is stronger than couplers if you can make it work.


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YJJPWrangler said:
It is for a traction bar since I am SOA in the rear. I agree that the traction bar x member will bear the majority of the load. I wanted to add the vertical bars between the two cross members so that there would be stiffness in the horizontal plane(for both cross-members).

Right now the transfer case crossmember can unbolt at the frame and be removed. The traction bar x-member will need to be welded to the frame. Bottom line, I was thinking that constant loading/unloading of the rear axle under acceleration/braking could potentially have a negative effect on a tubing coupler. From the responses, I shouldn't worry about it as long as everything is properly braced and supported.
Click to expand...


If it's a proper traction bar,

Then there should be a shackle at the X member connection.

This equals very little horizontal load.

The load would be upward during acceleration and downward during braking.

This is with a vertical shackle with frame mount below the traction bar mount on shackle.

I would guess frame flex during articulation would cause more stress on cross member and potential skid connection than the load on traction bar.
 
Mac5005 said:
If it's a proper traction bar,

Then there should be a shackle at the X member connection.

This equals very little horizontal load.

The load would be upward during acceleration and downward during braking.

This is with a vertical shackle with frame mount below the traction bar mount on shackle.

I would guess frame flex during articulation would cause more stress on cross member and potential skid connection than the load on traction bar.
Click to expand...

I'm planning on using the Barnes traction bar kit. That makes sense that the load would be more vertical than horizontal due to the shackle. As far as traction bar mounting goes, I'm planning on mounting it passenger side of the axle and crossmember. Am I thinking correctly that I need to mount the traction bar axle side somewhat in the middle between the pumpkin and the tire? I am thinking I need to favor the tire side more than the pumpkin side.
 
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