usings leafs as links? (1 Viewer)

[cruzerman350]

i am planning on doing a 3 link on the rear of my cruiser and im playing with a bunch of different ideas. first off can i use the leaf springs as the lower links if i cut them right after the axle? also with the top link can i run a triangle link? like one that goes from each side fo teh frame to the center of the axle? i would usea johnny joint on the axle for the link and jsut bushings where it attaches to the frame. i made the link in red and the leafs in blue. 569hw7.jpg][/url]



if that wont work does anyone have any better cheap ideas? i was thinking two link with a panhard bar but i cant afford that many johnny joints. stupid low paying job.

thanks
-miles

 

[BiffS]

leafs are simply not a good idea for that application. The lower links need to be rigid and are used to help locate the axle. if you were to apply torque to the axle through drive line forces, the leafs would bend and allow the axle to wrap: the whole reason for getting rid of leafs in the first place. the rear end would also have wicked death wobble under acceleration, likely leading to a crash or worse.

If you're low budget, best to stick with the leaf set up. a linked setup aint cheap to do properly. good quality steel for lower links will be thick (.385 or larger ideally). I paid $35 /ft for my .385 - 4130 cromo.

the triangulated link is not a good plan either, it will bind.

 

[Pacer]

leafs are simply not a good idea for that application.

thank you for taking the time

 

[Mace]

Leaves are bad but the triangle upper link is just fine...

the wall thickness of the tube also really depends on the OD of the tube...

A larger OD is harder to bend than a smaller OD..

 

[cruzerman350]

so if i run a 2" 3/8 wall tubing for lower links and for the triangular upper link all will work out? can i weld the lower links solid to the axle housing and do the same with the uper so the whole assembly just pivots?

 

[Mace]

Use some sort of joints at the axle end please..

 

[bustanutley]

first post very bad idea,
second post worse idea, won't even work, at all, the axle would only be able to move straight up and straight down down. You would end up tearing metal(scary)
you need to do some research,
linked suspension and cheep are not two phrases that go together, if you can't afford proper parts stick with leaf springs, they will work better(and safer) than some hacked together scary suspension.

 

[LC_Hamma]

Don't experience with new dude Whats wrong w/ a typical tried & true 4 link? Stay away from the panhard in the rear where you want max travel & you don't want one side kicking out due to the panhard swing. Run your J Joints at the frame & heims at the axle. I assume you're doin low co$t coil springs?

 

[Mace]

bushings on the axle end lowers are cheap and easy..

Then you can do bushings on the frame end of the wishbone (triangle)

You would only need 3 joints then..

 

[cruzerman350]

alright i was just thinking of ways i could do it easily. i have a set of coil springs and thats what sparked this whole thought process. most of the geometry i knew wouldn't work but i figured someone on here would know best and thats why i asked. all i want is more flex in the rear and right now it looks like im gonna have to just put my stock springs back on cause the springs that came on it are stiff as s***. im thinking leaf springs with a trac bar is my best option at his point. is 30% of flex out of a johnny joint enough to use on a trac bar or do i have to run a hiem joint?

thnaks for the input.

-miles

 

[bustanutley]

I use an RE joint on my wrap bar. It is basically the same thing as a johny joint, works fine. I think max it out but I do not need any more flex.

 

[BiffS]

im thinking leaf springs with a trac bar is my best option at his point. is 30% of flex out of a johnny joint enough to use on a trac bar or do i have to run a hiem joint?

thnaks for the input.

-miles

If you're thinking "track bar" which is also known as a "panhard bar" it's parallel with the axle (goes from side to side) and isn't needed in most leaf set ups. It will limit articulation severely and tug the axle to once side on the extremes of the stroke.

a "wrap bar" or "traction bar" set up runs parallel with the drive shaft; from the front to the rear of the truck and is a good idea with leaf set ups, especially if you're sprung over. This helps prevent axle wrap which can break pinions and u joints.

the 30 deg. travel of JJs and RE ends is considerable when you factor in that 30 degrees of axle articulation in each direction is virtually the equivalent of almost 35" of tire travel from stuff to droop.

 

[cruzerman350]

thank you for the info. i am going to make a traction bar with a johnny joint. is there any specific length i should make the shackle? ive seen pictures or traction bars with a shackle and im wondering if longer or shorter would be better. also does the form bracket have to be in any specific spot?

thanks
-miles

 

[BiffS]

that's one place that you can save money and use a heim joint at the transfercase side and rubber bushings at the axle side.

length should be as long as possible, and you can use a standard shackle (5-6") at the transfer case side.

 

[Mace]

longer and flatter is better,

Shorter, with a serious upward angle will control axle wrap but will create wheel hop..

 

[lcwizard]

The only reason I know of to incorporate i leaf into a linked rear is to use it in place of a coil . It which case you need to run a shackle on each end of the leaf. This allows the axle to swing freely front to back with the arc of suspension travel that will be determined by your links. In a space limitted situation
where a tall coil just won't fit, or you just can't afford one, this works well. I set up a FJ40 rear using a reworked (leaves removed) chevy 52" leaf pack and got just under 16" of linear travel which is about 24" of articulation.
You will need to tub the rear for this

 

[redline fj55]

i am planning on doing a 3 link on the rear of my cruiser and im playing with a bunch of different ideas. first off can i use the leaf springs as the lower links if i cut them right after the axle? also with the top link can i run a triangle link? like one that goes from each side fo teh frame to the center of the axle? i would usea johnny joint on the axle for the link and jsut bushings where it attaches to the frame. i made the link in red and the leafs in blue. 569hw7.jpg][/url]



if that wont work does anyone have any better cheap ideas? i was thinking two link with a panhard bar but i cant afford that many johnny joints. stupid low paying job.

thanks
-miles

this is the swing arm i am using on my fj55

 

[cruzerman350]

does anyone have a CAD drawing for a traction bar bracket? i have access to a plasma table but i don't have the CAD program on this computer.

a bracket like this one




also if anyone needs some of those brackets i can make a few.

thanks
-miles

 

[bustanutley]

I don't have a drawing of it but I could make one real quick for you if you like, what is the diameter of cruiser axle tubes? 3.5" I think?

edit:
If I threw a few bucks at you would you make me a pair as well?

 

[fj40forlife]

C.A.D= cardbored and ducktape =]
I think have some drawen out. have to check

Eric