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Let's talk about link suspensions without coilovers

Lil'John

Former #278
Joined
May 20, 2020
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488
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Walking to the Rubicon
Title is the short version.

Longer:
I'm doing a "cheap" link suspension where coilovers aren't on the table... I actually have a set on the shelves for a different project but they will be too long for this project; zero lift project won't fit 14" coilovers:lmao:

I'm strongly looking at the early 90s quarter leaf setup since I have "free" springs... aside from the 90s screaming out in pain, is there a downside? An upside to me is ability to "cheaply" tune them(add/remove springs)

I know there is also coil springs. Packaging to me is a bit more of an issue. My rig isn't full width. Tuning is a bit of an issue so it feels more like guessing and going back to the junkyard.

There is also air bags. Not really on the plate due to needing onboard air.

Any other options?

How about torsion bar setup like Chevy IFS.
 
It all works. Its all just a way to get a spring rate so I'm not sure there is really any advantage to one over the other besides what you can fit in the chassis. Coilovers will always win out in that discussion due to packaging and tuneability. While 1/4E is tuneable its difficult to know what changes will do what in the end, whereas coilover springs are usually known rates and lengths.

Kevin
 
how does a shock capable of the travel fit but not a coil over?

there are a lot of LJ, TJ, and JKs running around with coils that ride and function well. as Ghetto Fab mentioned, the down side to those options is spring rate selection, which in turn drives suspension performance.

there was a TT team back in the day that used torsion bars

https://www.race-dezert.com/forum/threads/baldwins-race-truck.5270/
 
how does a shock capable of the travel fit but not a coil over?
Basically, in order for me to use a 14" travel shock in this project, I'd have to have the top of the shock coming out a ton.

I can't find the pictures of my friend's rig that is almost the exact same setup; rig and coil over front. But he had his lifted ~4" more than mine and had ~3" of coilover through the hood.
 
is running a 12' shock a possibility? id run a short traveled air shock (full set would be around $1k) for a simple buggy before all the other variants that we saw in the 2000s
 
Found a picture of buddy's rig(I can't find hood/shock picture):
don55_sml.jpg

Mine will be similar setup but drop it ~4". You can barely see the shock hoop on the hood between headlight and turn signal.

But to repeat: I've got 14" travel shocks but they will go through the hood by a lot. I don't want to buy shorter.
 
is running a 12' shock a possibility? id run a short traveled air shock (full set would be around $1k) for a simple buggy before all the other variants that we saw in the 2000s

In my case, not strictly a buggy ;) I think this weight over the front will be too much for an air shock:
Plow_sml.jpg
 
Mine will be similar setup but drop it ~4". You can barely see the shock hoop on the hood between headlight and turn signal.

that lower mount is a foot off the axle, which explains why hes through the hood.

so its going to be a fat pig, plow on the front in the winter, stock width axles, you want to be able to articulate with a 14" shock while keeping it relatively low? that is a tall order. i link the front of a 1st gen 4runner, stock width, a custom tube frame frame with a 12" coil over and it was TIGHT. what is the goal of the build?

i dont recall seeing anyone running a quarter elliptical on the front, the rear yes, but not the front.

https://forum.ih8mud.com/threads/it...motor-swap-aka-ak2al-aka-dream-build.1191428/ - buddy built this and it is fairly low, maybe consider using some stock toyota drivetrain stuff.
 
that lower mount is a foot off the axle, which explains why hes through the hood.
Good eye... I'll have to take another look for the other pictures I have of it.

so its going to be a fat pig, plow on the front in the winter, stock width axles, you want to be able to articulate with a 14" shock while keeping it relatively low? that is a tall order. i link the front of a 1st gen 4runner, stock width, a custom tube frame frame with a 12" coil over and it was TIGHT. what is the goal of the build?
God no.

It is going to be much less body than the linked one I show above... I can't comment about weight because he has done a ton of work to lighten it up. Mine is going to lose most of the roof for a "truck" cab size. It is going to lose 16" off the ass behind the axle. There won't be a rear door ;) The axles are 60" wide Dana 60s. I expect maybe 3-4" of up travel and who cares how much down.

I have the 14" shocks on the shelf for my other rig: same base similar to the above except with 43" TSLs, full width Dana 60s, and a bit of lift ;)

The goal of this rig is to beat it up plowing and being able to do slightly stupider things on Rubicon/Fordyce than my daily rig:
Outside1.jpg

This linked version is trying to be ~4" shorter than the above rig.

i dont recall seeing anyone running a quarter elliptical on the front, the rear yes, but not the front.
Back in the day, I usually saw rears getting linked first. I haven't looked for a front quarter elliptical.

https://forum.ih8mud.com/threads/it...motor-swap-aka-ak2al-aka-dream-build.1191428/ - buddy built this and it is fairly low, maybe consider using some stock toyota drivetrain stuff.

If this is the one I think it is, I haven't browsed it much. I'll have to take a look.
 
Cantilever/bell crank with coilovers an option? You can screw around with the motion ratio and linkage angles to fit just about anything. I'd think if you can fit a 1/4 elliptic, you could probably make this work too.

Click image for larger version Name:	10688853.jpg Views:	0 Size:	141.6 KB ID:	178510
 
well then id do spring under in the front and link the rear with 1/4 elliptical. keep it simple
 
Cantilever/bell crank with coilovers an option? You can screw around with the motion ratio and linkage angles to fit just about anything. I'd think if you can fit a 1/4 elliptic, you could probably make this work too.
With enough money, anything is possible:homer: I'm not sure I've ever seen a cantilever/bell crank setup in the front. Unlike the back/under a bed, the engine/transmission gets in the way.

well then id do spring under in the front and link the rear with 1/4 elliptical. keep it simple
I've seen two or maybe three front Dana 60 sprung under. The issue is the the spring pad is in the diff housing. Everything I've seen make it looks like a complete pain in the ass to do... plus having the skill to weld on the cast housing. I don't have the skill for cast welding nor does my local buddy(ie cheaper cost). My axle guy(WelderBill) absolutely has the skill but I'm afraid to see what the cost would be.

My goal on my project is keeping it cheap.

FWIW, short of some sway bar mounts on the axle, the rear is in and sprung under:lmao:
 
Missed the front end part.

So where would you clamp/fix the half leaf spring end to? Behind or in front of the axle?

I'm thinking 'behind' would mean a whole ton of cantilevered weight hanging past the spot where the spring acts on the chassis, so it'd be a helluva heavy spring and a lot of unsupported chassis rail...or 'front' would mean you've got what, 2-3 feet of frame in front of the axle?

I like the 1/4 idea but packaging seems pretty difficult.
 
Missed the front end part.

So where would you clamp/fix the half leaf spring end to? Behind or in front of the axle?

I'm thinking 'behind' would mean a whole ton of cantilevered weight hanging past the spot where the spring acts on the chassis, so it'd be a helluva heavy spring and a lot of unsupported chassis rail...or 'front' would mean you've got what, 2-3 feet of frame in front of the axle?

I like the 1/4 idea but packaging seems pretty difficult.
Good questions.

I'm still scratching my head on mounting options for the 1/4. My initial thought is solid mount the spring to the axle using "stock" spring perches then put a shackle at the frame.

For springs, I've got a set of F-350 rear springs that I am considering cutting up (~65" long and 3" wide)

The amount of front frame horn depends upon where I drop the axle. I'm still in flux on where it will land. But it will be between 24" and 28".
 
I think you'd be better off mounting the leaf under the frame then run a shackle behind the axletube.

Better yet though, see if you can mount coilovers behind the axletube. I know its a jeep thing, but JKs have been doing this for awhile and I bet they have less axle to hood height involved than your fj55. They also have a ton of other crap like fuse boxes and body computers in the way and they still make it work.

Kevin
 
I've seen two or maybe three front Dana 60 sprung under. The issue is the the spring pad is in the diff housing. Everything I've seen make it looks like a complete pain in the ass to do... plus having the skill to weld on the cast housing. I don't have the skill for cast welding nor does my local buddy(ie cheaper cost). My axle guy(WelderBill) absolutely has the skill but I'm afraid to see what the cost would be.

My goal on my project is keeping it cheap.

FWIW, short of some sway bar mounts on the axle, the rear is in and sprung under:lmao:

Spring over then. What's the issue with the perches? Can the springs be out boarded?
 
I think you'd be better off mounting the leaf under the frame then run a shackle behind the axletube.
I've got a plan for that variation also ;) I just keep jumping between the two plans.

Better yet though, see if you can mount coilovers behind the axletube. I know its a jeep thing, but JKs have been doing this for awhile and I bet they have less axle to hood height involved than your fj55. They also have a ton of other crap like fuse boxes and body computers in the way and they still make it work.

I could probably get them to fit... just cut more of the inner fender than I have already:homer: I'll see if my current cuts will allow me to show a mock up.

The problem with the 14"x2.5" Kings that I have is they are set for a rig with an LS engine and 43s while the rig I'm building is using a big block cady and 35s plus a snow plow... that extra weight over the front axle probably kills the 200/250 springs.

Another concern I have is more than likely needing to make a "shock" brace that is going to span the engine bay.
 
The problem with the 14"x2.5" Kings that I have is they are set for a rig with an LS engine and 43s while the rig I'm building is using a big block cady and 35s plus a snow plow... that extra weight over the front axle probably kills the 200/250 springs.

But that's easy to change. Sure you need to spend more $$$, but you could sell the coils you have to recoup some $$$ and at least you know what spring rate you have and where you most likely need to go. With leafs you won't know any of that, and with factory coils you have limited selection.

Kevin
 
You can pick up stock shocks and springs for any of the new pickups. They are basically non adjustable coil overs. People throw them out all the time or sell for dirt cheap. You can put them on a link or cantilever to change the ratio. Tacoma for light vehicles and Tundra for heavy vehicles. Many are Bilstein from the factory. Or get some Raptor shocks and coils.
 
The one thing about a QE spring setup vs. air or coilover that intrigues me is once you go past the spring's normal state from compression to droop you get negative spring force pulling the axle back up in droop that can help with stability. This can be tuned with leafs under the "main" spring.

You can do similar things with a small height coil spring with solid mounted ends but I think it damages them to stretch the coil.

Hopefully that makes sense, packaging of QE is still tough... as well as deciding how long to grow out your mullet.
 
I'm in the planning stages of a LJ built. I have a buggy and Jeep on coilovers. I will not be using coilovers on the LJ. It will be long links but will keep a traditional coil spring. There are tons of spring for the TJ / LJ platform. Lots of lengths, rates and even progressive available without breaking the budget. Spend the saving on shocks that can be tuned.
 
The one thing about a QE spring setup vs. air or coilover that intrigues me is once you go past the spring's normal state from compression to droop you get negative spring force pulling the axle back up in droop that can help with stability. This can be tuned with leafs under the "main" spring.

You can do similar things with a small height coil spring with solid mounted ends but I think it damages them to stretch the coil.

Hopefully that makes sense, packaging of QE is still tough... as well as deciding how long to grow out your mullet.

Good point about spring fatigue. I was planning on running limiting straps to keep the springs within a reasonable range.

The packaging between a QE and plain coil seem to be the same "effort" to me. A plain coil needs a big bracket off the frame horn and a bucket on the axle. The QE needs a bracket on the frame to "pinch" the spring on and a shackle mount on the axle.

Sadly, I've got all my teeth and rock a bowl hair cut😂

I'm in the planning stages of a LJ built. I have a buggy and Jeep on coilovers. I will not be using coilovers on the LJ. It will be long links but will keep a traditional coil spring. There are tons of spring for the TJ / LJ platform. Lots of lengths, rates and even progressive available without breaking the budget. Spend the saving on shocks that can be tuned.

This rig isn't really destined for anything fancy unless my welding skills get 10x better:lmao:

Actually, because it is a "ranch" truck, it is getting the cheap treatment. Maybe in 5 years after the real rig gets wrapped up, this will get coilovers.
 
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