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master_mechanic 07-04-2009 07:46 PM

12 inch lift springs
A buddy of mine is in the middle of building a 1979 ford f-350 with a 12 inch supension lift, problem is the rear axle wraps extremly hard on even slight acceleration... does anyone know of a comapany that makes traction bars for somthing like this or has anyone made their own that would like to help me out with some ways to build my own. thanks

Dave Sponaugle 07-05-2009 12:51 PM

Might want to consider this.

The springs on that truck were 20" lift if I remeber right.
And yes they got the tire clearance he needed.
But when you start looking at the shackle length, the springs were almost rigid.
The shackle was not long enough for the spring to be able to flex.
3" shackle let the spring end move back and forth about 4" which turned into about 2" of axle movement before the spring was binding against the frame either compressed or extended.

It really did not work well at all.

6 heim joints and some double wall tubing, he manufactured a three link system to stop axle wrap.
But that was the least of his problems.

75F350 07-06-2009 04:55 PM

Make your own:

master_mechanic 07-07-2009 07:19 PM

does that limit your travel at all? how well does it work offroad? thanks

75F350 07-07-2009 07:30 PM

If you are asking me, then my answer is yes. This design did limit articulation to some degree.
It has since been modified with a shackle on the upper ends. The original design was designed to be used with a shackle, however the shackles were not installed. They were not installed because I missed a small detail and my dimensions were off. The traction bars that I made were actually designed as replacement tie rods. My tie rod is the exact same dimension. During heavy trail use, if I bust or have a failure, I can easilly replace it with one of these as spares.
Thed esign is not the best and has been modified.
I am currently working on a three link design, but had a failure during some tests. The three link seems to fold up under extreme wheel speed. Back to the drawing board. No mud right now, so tests will have to wait for a bit.

master_mechanic 07-07-2009 07:50 PM

Thanks for the info, it helps alot. where exactly does the upper end of that rod attach to? did this set up keep the axle from trying to jump out of the truck and did it atleast work for the mud?

75F350 07-07-2009 08:15 PM

It worked well in the mud and it worked suprisingly well in the sand. I run a 557 BBF and I hit it with 300 HP of nitrous. When traction is good, its hard on parts to say the least.
The limited travel was not so good in the rocks and twisty trails. I supose that it probably was not all that great in rutted mud where additional axle travel would have been better.
My attempt at keeping the bars high enough to help maintian some clearance was a reasonable idea, but it still has some bugs to work out.
The big motor makes a bucket load of torque and wheel hop was ever present. Again these helped but had some design problems.
The top attached at a custom crossmember that bolts to the inside of the frame rails. This also added rigidity to the frame and helped to eliminate the dreaded frame flex.

Some preload was placed upon these bars, and this too limited suspension travel, but helped a ton with putting traction to the ground and keeping the 44's under control.
At one time the truck had a bunch of body roll, it would lift the inside front tire under some full throttle passes. Adding pre load helped reduce this.
I have the spring rates figured out now, and with any luck the new design traction bar will help. Its all about trial and error, and being able to admit when you have a poor design, or at least being able to accept the fact that there is roomm for improvemnt. Mine leaves much room for improvement, and I am aware of it.
I believe that trucks with highly arched springs and limited articulation already can benifit from this simple design.
I run a fairly flat spring, so the axle does not move towards the shackle end too much, but the angle of the bars require a slightly different arch of motion than the springs will permit. Its a razors edge, but a floating design, or a shackle on the upper end should provide more than enough motion to permit adequate movement.

My new design actually incorperates a splined section, and a Johnny Joint. Just gott work some of the design bugs out. Still have a problem with trying to fold it up like a pretzel, but trial and error can be fun. I guess only when it works, not much fun when failures occur, but it is what it is.

1979super4x4 03-02-2011 12:47 AM

i dont have any pics loaded yet of the traction bars but i got around 8 inch springs and 5 in block on the back of my 79 f250 supercab longbed and i used 2x2 square tubeing a 7/8 in weld on top link replcement from a farm store cut the stock shock monts off and welded a new bracket and put the frame mount at the edge of where the frame starts to angle up
they work good only down side is nonadjustable but they only coast round 50 bucks to build

Redneck86 03-02-2011 07:21 PM

You got any pics of your truck? Been thinkin about a set of either 6 or 8in springs for mine after I finish the motor.

fatdan460 03-02-2011 07:58 PM

hey redneck, i got a place where you can get 4'' or 6'' s/d front leafs for that truck for like $250-280 a pair shipped. they are damn near a bolt in for the leaf sprung front 79's and older. let me know if you are interested.

captain p4 03-03-2011 12:05 AM

What ever happened to Ed?

fatdan460 03-03-2011 12:43 AM

he attacked a couple messicans that were trying to steal his welder in the middle of the night and that was the last i have seen him post on here or fsb. and that was months ago. ask chasetruck, i think they hold hands and double date on the swings at the park.

alpha/omega 03-03-2011 04:17 PM

I got tired of him swinging on my schnuts so I shook him off into oblivion.

Redneck86 03-03-2011 07:21 PM

Originally Posted by fatdan460 (Post 10042477)
hey redneck, i got a place where you can get 4'' or 6'' s/d front leafs for that truck for like $250-280 a pair shipped. they are damn near a bolt in for the leaf sprung front 79's and older. let me know if you are interested.

Yeah I may be interested in the 6ers, especially at that price. Still getting a plan of attack together for the motor, sometimes I hate living right by summit racing lol.

alpha/omega 03-03-2011 07:59 PM

Summit also has Procomp 4 and 6" springs for about $120 ea

Pro Comp Suspension Systems 22410 - Pro Comp Lifted Leaf Springs - Overview -

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