track bar ?'s (1 Viewer)

[chicago]

Hey all,
Im normally on the 60's forum, but I thought these questions would be more thouroughly covered here.
I ran a search on traction bars, but I had a few additional questions.

1) Why is a shackle style hanger recommended off of the cross member? It seems that it would defeat the purpose, unless it is a fixed base. Or is that the point that Im missing?

2) Johnny Joint? Is that the fixed joint on the axel housing with the bushings?

3) Heim Joint? like the tie rod ends...correct?

4) Where can you get above joints?

5) Does a new cross member need to be made for a track bar?

6) What is "anti squat"?

I have an 88 FJ 62 that Im going to be doing an SOA on, and I want to have all the info I need before I start and consider all necessities required to do this right.
This is my first "BIG" project, and Ill be doing it my self, so...Im a little anxious.
For a design, Im thinking Im going with a "ladder style" track bar using the brackets from "ruffstuff specialties". That seems, to me, to make the most sense from a design stand point as there is bracing from both the top and the bottom.

Thanks for your help in advance!

Chicago

 

[CaliCruiser]

https://forum.ih8mud.com/showthread.php?t=75246&highlight=trac

this is a great thread. I learned a lot about the design and purpose of a anti wrap bar.
The purpose of the bar is stop the axle housing from twisting when the torque/power is applied. The shackle still lets the rear suspension flex and not bind.
Heim joints are the joints where you weld the bung into the tubing and and it has an eyelet that bolts to the shackle and allows a lil more flex and less bind.
Rubicon express has both johnny and heim joints along with any other 4wheel shop.
I plan on adding a new crossmember, I believe this is the choice for sixty series.
still confused about anti-squat


HTH

Dylan

 

[rusty_tlc]

Anti Squat:
When you put the springs on top of the axel the rotation of the tires tries to bend the springs into an "S" shape under acceleration. This also happens when you are SUA but it is very pronounced when you are SOA. The result is that the rear of the rig feels like it is dropping, or squatting, when you accelerate. A traction bar limits the amount of rotation around the axel without limiting the axel travel with respect to the frame.

 

[chicago]

Ok,
That is easy...Its just another term for axel wrap then, yes?

Chicago

 

[chicago]

https://forum.ih8mud.com/showthread.php?t=75246&highlight=trac

this is a great thread. I learned a lot about the design and purpose of a anti wrap bar.
The purpose of the bar is stop the axle housing from twisting when the torque/power is applied. The shackle still lets the rear suspension flex and not bind.
Heim joints are the joints where you weld the bung into the tubing and and it has an eyelet that bolts to the shackle and allows a lil more flex and less bind.
Rubicon express has both johnny and heim joints along with any other 4wheel shop.
I plan on adding a new crossmember, I believe this is the choice for sixty series.
still confused about anti-squat





HTH

Dylan

Hey Dylan,
I found and read that articel twice when i ran the search...It is a very good article. The questions I had above are residual after reading that post.
Thanks for the info.

Chicago

 

[Mace]

1) the flex of an axle does not travel in a perfect arc. And, even if they did finding the exact radius of the arc is kinda tough.. So you add a shackle on the frame end to reduce binding and distortion of the springs. since the bar is hard mounted to two places on the axle, a shackle does not reduce the antiwrap capcbilities of the bar.

2) Johnny Joint is a type of cartridge joint ( sort of similar to a rod end) made By currie enterprises. For a ladder style track bar you only need one. Mount it at the shackle and mount the axle points with poly/rubber bushings..

3)TRE's are like what is on your steering. Easy answer is they are a ball joint with a stud mounted in single shear. Rod ends used for our applications generally look like an Eye bolt with a spherical ball in the middle of the eye. They need a bolt to mount to anything and are typically mounted with metal on both sides of the rod end (double shear)

4) Blue Torch Fab, Rockstomper.com, Poly performance among a TON of other vendors. QA-1 direct for rod ends. Lots of options, go peruse the vendor section and see who floats your boat

5)To make a truly strong Trackbar I reccomend that you do make a new X member. The stock one is kinda weak and typically rusty by now. Now this does not mean that it won'o work, but a new x member is a good idea.

6) AS is only sort of dependant on the springs. Only because they are links. It is not a cause of the spring distorting. That is axle wrap.

AS is a issue with link design. When you make a Anti Wrap bar (traction bar) you are basically designing a simple linked suspension. By moving the bar locations (both axle and frame) you can vary the amount of AS. There is a lot of mathematical equations involved in this that we can go into if you want but the simple answer is AS is the force that reduces the habit of a vehicle "squatting" under acceleration. Large amounts of AS actually have the venicle "raise" when you step on the gas. Which, dependong on who you are talking to is either good or bad (it is suggested that when you push the ass end of the truck up you are pushing the axle down increasing traction) Now, one of the complications of large amounts of AS is wheel hop. Basically, when you go to climb a steep incline the truck can buck and "hop" and break things..

High AS #'s are typical with a track bar. so limit the droop with a center strap and call it good.

 

[chicago]

OK Mace,
I was following along pretty well until you said that last part...What is a center strap? Is that another term for traction bar?
As for the x member, I was looking under the rig last night trying to find a good way to mount it...
On my 62, the inside of the passenger side frame, all the brake line run there. Here's what I was thinking...I could get a 1/4 in plate behind there, and one on the outside frame, and use 4, 1/2 in bolts to secure it, and then fab a x member from there.
I have a few questions about that...

1. How far out should the x member be from the axel?

2. Should the x member sit up into the frame, or below it...in other words, should I run it up along the under side of the tub, or down on the frame rail and have the shackle mounting point hang down?

I dont have a whole lot of options for mounting the x member unless, I can somehow go over the top of the break lines. Then on the pass side, there is the exhaust and muffler. It seems like it can be done, but I just worrie about having ample strength

Will drilling holes in the frame weaken it?

Chicago

 

[lowtideride]

I mounted my x-member a few inches behind the t-case. It is attached at the top of the frame(above the brake lines, wasnt fun to weld). My wrap bar runs about a 1/2 above my drive shaft the whole way up til meets the x-member.

The limiting strap is a strap going from the center of the axle to the frame. It limits how much the axle and drop, while also helping to eliminate wheel hop.

 

[lowtideride]

Also dont be afraid to over build it. I used 3/16 steel for a braket on the axle tube and last time at tellico I tore the metal in half like it was paper....the wrap bar survived 2 years, but the lower gearing and bigger tires helped do it in...

That rock wall dint help either on upper 2 that also took out my door and window

 

[Mace]

You really want your bar to be as long and as flat as possible (reduces AS) however that really depends on where it will fit.

LT had it right. A limit strap goes in the center of your axle to the frame (straight up) it reduces the ability of your rear axle to droop but only when it is both sides at once. Think of it as a pivot for the axle. Either side can droop nicely but both can't at the same time.
The strap basicaly creates a limit for "lifting" forces when accelerating. So most of the energy that creats wheel hop is stored in the strap..


Frames are tough. Holes are fine.

Build it strong, It sucks when it fails on the trail..

Clear as mud?

 

[chicago]

I had to read it a few times, and think about it quite a bit, but I think I got the idea of a limiting strap...I really dont know how to compare it, except, maybe a soft tail motorcycle vs a hard tail. I essentially locks the center of the axel in onse stationary position while allowing the ends of it to move up and down. Correct? Ive never heard of this before.
As for the x member...Do you think if I took 1/4 in plate and welded shims to the back side of it to clear the break lines, I could bolt on a spot to mount the x member...In other words, I would be covering up the break lines with this plate and using it as a mounting point as opposed to the frame. My thought is, I could then run the x member up higher and also be able to gusset it at the ends...What do you think about that...And use 1/2 in bolts THROUGH the frame?

Thanks Mace and Lowtide for the info...

Chicago

 

[rusty_tlc]

I had to read it a few times, and think about it quite a bit, but I think I got the idea of a limiting strap...I really dont know how to compare it, except, maybe a soft tail motorcycle vs a hard tail. I essentially locks the center of the axel in onse stationary position while allowing the ends of it to move up and down. Correct? Ive never heard of this before.
As for the x member...Do you think if I took 1/4 in plate and welded shims to the back side of it to clear the break lines, I could bolt on a spot to mount the x member...In other words, I would be covering up the break lines with this plate and using it as a mounting point as opposed to the frame. My thought is, I could then run the x member up higher and also be able to gusset it at the ends...What do you think about that...And use 1/2 in bolts THROUGH the frame?

Thanks Mace and Lowtide for the info...

Chicago

I'll phrase this as a question for the more learned members since I'm not entirely sure of the answer.
If Chicago bolts through the frame should he tube the bolts, that is weld a piece of pipe or tube between the two frame sections to keep the bolts from loosening up over time? Same as when people do a PS conversion on a 40.

BTW if the tubes extend inside the frame they would also provide clearence for the brake lines.

 

[lowtideride]

Sorry for the crappy pics, I will try to grap some better ones of the cross member.

 

[chicago]

Thanks for the pics lowtide!
Its tucked up there pretty high! Is it welded to the frame, or is it bolted? Those damn brake lines are KILLING me. I made a mount to go on the bottom of the frame rail that bolts through, in between that 2 in space between the lines. Im still considering ideas for this though and Im hoping that some things will be easier when Im doing the SOA and I have the DS out and stuff.

Thanks again,

Chicago

 

[woody]

center limit:

allows for unrestricted compression of the axle (to the bumps)
allows for maybe 1-2" of extension of the axle, at the middle
has a near-zero limit on articulation or ride

I run a center limit both front and rear on my suspension, front is SOA and rear is linked...the limit in the rear has about 1" before it's tight, the front about 1.5"...I use ALL of my 14" stroke shocks at all 4 corners and can easily park a rear tire 60" in the air with the other 3 on the ground. it SUCKS for jumping/highspeed whoops-type drivin (since the limits get hit a lot) but for street or trail use, it's great.

you can purchase nice straps for $25ish, or bootyfab a chain and accept the noise and harsher limit. I run a strap in the rear and a POS chain in front...lol

 

[lowtideride]

Thanks for the pics lowtide!
Its tucked up there pretty high! Is it welded to the frame, or is it bolted? Those damn brake lines are KILLING me. I made a mount to go on the bottom of the frame rail that bolts through, in between that 2 in space between the lines. Im still considering ideas for this though and Im hoping that some things will be easier when Im doing the SOA and I have the DS out and stuff.

Thanks again,

Chicago

Its welded to the very top of the frame. I notched it so half of it sits on top of the frame, and the other half is welded to the inside of the frame....if that makes anysense.

 

[chicago]

yeah,
that kinda makes sense...like a piece of angle iron on the frame right?

Chicago

 

[chicago]

center limit:

allows for unrestricted compression of the axle (to the bumps)
allows for maybe 1-2" of extension of the axle, at the middle
has a near-zero limit on articulation or ride

I run a center limit both front and rear on my suspension, front is SOA and rear is linked...the limit in the rear has about 1" before it's tight, the front about 1.5"...I use ALL of my 14" stroke shocks at all 4 corners and can easily park a rear tire 60" in the air with the other 3 on the ground. it SUCKS for jumping/highspeed whoops-type drivin (since the limits get hit a lot) but for street or trail use, it's great.

you can purchase nice straps for $25ish, or bootyfab a chain and accept the noise and harsher limit. I run a strap in the rear and a POS chain in front...lol

Woody,
Thanks for the info...
I have to be honest, Im having a very hard time visualizing what the strap looks like and where its attached on the rig.
My impression from above, is that It is a solid bar, tupe or pipe that almost fiixes the axel and allows it to pivot vertically end to end, but stops the center from compression and thus, prevents AS? I think Im off somewhere...Do you have pics of yours?

Chicago

 

[woody]

nope nope nope....

picture a 12" piece of snatch strap....with eye's on either end

one to a crosstube directly above the axle housing, centered...

the other, directly to the center of the housing...

at ride height, it's not tight...but lift from the frame and it tightens almost immediately

 

[woody]

http://www.bluetorchfab.com/oscomm/catalog/product_info.php?cPath=126&products_id=202