V-link Front Suspension

[Walking Eagle]

Ok, been thinking and thinking and thunk most things that can be thought.... and this is what I came up with.....

1/2 x-link design, 1/2 y-link design, all with keeping the stock arms as a base.

Unlike the Y-link radius arm set-ups you see on jeeps, it's one piece and puts the joint right above the differential - though maybe that's not the idea spot, maybe it's better off to the left side, since the diff is offset to the right.

It's sorta like the x-link and cranky-link with the single center mount, but it's in the opposite direction as what they put the bushings in. With a johnyjoint in that possition, axle wrap will be more controled, yet there should be plenty of rotation in the joint, expecially with johny joints at the mounts to the stock arms adding missalignment potential.

I think it'd work, it's just a matter of can you get all the tubing to fit under the truck without taking out a swaybar or oil pan...

Whatchall think? Should I try it, or just go have another beer and forget about it?

[Isotel]

it seems like it would be easier to Cut off the second radius arm mount, and build a 3rd link..

there is alot of stuff in the way of your design, like steering, oil pan, panhard, and your 3rd member is not centerd like that..

Keep Drinking its always good to think outside the box!

[LT]

If you want to put a true 4 link under an 80 series you can't think of the traditional way of a 4 link. With this way of thinking you have the upper flat on towers so they are perfectly horizontal and the lower triangulated to a lower sub frame coming below the engine. This way you can get the triangulation and the cycle of a 4 link.

[Nay]

I think you should do it

[NW-sickboy]

why wouldnt you just 3-link it?

[CreeperSleeper]

Originally Posted by LT

If you want to put a true 4 link under an 80 series you can't think of the traditional way of a 4 link. With this way of thinking you have the upper flat on towers so they are perfectly horizontal and the lower triangulated to a lower sub frame coming below the engine. This way you can get the triangulation and the cycle of a 4 link.

I don't think they get it, LT... You better do it on mine so you can show them!

[boydmick]

I'm probably missing something here but. . . . . .

Isn't the stock LCA one of the major limiting factor for flex?
I think a Johny joint would help, but you're still only gonna get minimal rotation at the rear due to clearance at the bracket/arm interface.

[LC80Ducati996]

The stock LCA limits flex and ground clearance.

IMHO build a beefy stand off to mount to the stock lCA mounts on the axle but sits on top of it. Pivot point of new mount above and aft of the axle centerline a touch. Make a simple set of straight arms with johnnys to go from stock location to them. Then fab your third link mount on the axle. Use the 3 link calculator from pirate forums to get it tuned right before you build.


I'd only do a triangulated 4 link in the back. Up front you need a panhard to keep the drag link happy so no gains going to a tri 4 there or even a straight 4 link. 3 links dont look that bad on these.

In back I really think the best thing to do is flip the idea around and do it like the road racers do. Angle the lower arms inward big time and the uppers outward a touch. Best fit around everything. Calcs on the Excel version of the 4 link calculator confirm that if done and tuned right it will have great results.

[Clutchee]

You might wanta talk to Carl @ Outback Offroad Gear
His wifes 80 has a 3 link under the front it-did well at GSMTR this year.

[Dusty]

wont work. start over

[ginericLC]

I think you should just forget about it. You really don't need any more flex than what you have for the wheeling in your area. Seriously, is doing all this work going to get you further down the trail somehow? Is it going to open up a whole new set of trails? If not, why do it? And really what is the point. Unless you are going bigger than 35s you won't be able to take advantage of this new found flex. So you gained some flex, you still did nothing about axle clearance. It is my opinion that the 35" tire is the max before you lose good highway manners of an 80. And after that point things get real expensive, better be looking at Longfields, axle upgrades, etc... Boy I'll make a lot of friends with this statement, Unless you are going bigger than 37s you aren't going to get a full bodied 80 much further down the trail than one on 35s. But what the heck do I know, I'm driving a 100 now.

[ls2gto]

I think its just the engineering spirit more than how far you can get down the trail. I get it. I've been wanting to attempt something like this, but can't get over the safety factor of the only thing keeping this front end under me at 80 mph in a 6000 lb high cg vehicle is my welds. I'd venture to say that's why Heath is looking to keep his stock arms, but I could be wrong.

I say go for it. Is there a decent way to mock something up and put it through the motions? I've heard of using lego's but there has to be a better way.

Originally Posted by ginericLC

I think you should just forget about it. You really don't need any more flex than what you have for the wheeling in your area. Seriously, is doing all this work going to get you further down the trail somehow? Is it going to open up a whole new set of trails? If not, why do it? And really what is the point. Unless you are going bigger than 35s you won't be able to take advantage of this new found flex. So you gained some flex, you still did nothing about axle clearance. It is my opinion that the 35" tire is the max before you lose good highway manners of an 80. And after that point things get real expensive, better be looking at Longfields, axle upgrades, etc... Boy I'll make a lot of friends with this statement, Unless you are going bigger than 37s you aren't going to get a full bodied 80 much further down the trail than one on 35s. But what the heck do I know, I'm driving a 100 now.

[Nay]

Originally Posted by ls2gto

I think its just the engineering spirit more than how far you can get down the trail. I get it. I've been wanting to attempt something like this, but can't get over the safety factor of the only thing keeping this front end under me at 80 mph in a 6000 lb high cg vehicle is my welds. I'd venture to say that's why Heath is looking to keep his stock arms, but I could be wrong.

I say go for it. Is there a decent way to mock something up and put it through the motions? I've heard of using lego's but there has to be a better way.

The engineering spirit is what gets you from 90% wheeling / 10% wrenching to 90% wrenching / 10% wheeling.

[ls2gto]

very true..

Originally Posted by Nay

The engineering spirit is what gets you from 90% wheeling / 10% wrenching to 90% wrenching / 10% wheeling.

[udm (nsw)]

by the looks of it, i reckon the red bar will act as a swaybar.

[Walking Eagle]

Originally Posted by NW-sickboy

why wouldnt you just 3-link it?

Simplicity. Could just fab up the V-link while everything else is still attached, then once it's all welded on (by someone better at welding than I), just cut the stock arms. Really no calculations to be made at all.

Originally Posted by ginericLC

I think you should just forget about it. You really don't need any more flex than what you have for the wheeling in your area. Seriously, is doing all this work going to get you further down the trail somehow? Is it going to open up a whole new set of trails? If not, why do it?

I'd disagree that I don't need any more flex for wheeling in my area. All this work is going to get me 4 wheels on the ground in places where right now I'm three wheeling, or teetering on two. Why do it? Why not? Part of it is that the rear flexes so good, that the whole thing seems unbalanced. Especially stepping up or down ledges. The one tire going up first or down first tends to throw the body to the side. I want to free it up a bit so the body can stay level long enough to get the second tire started.

oh, and I'm going down that MIBS road to 37's in the spring when my current tires wear out. I'm thinking 37x13.50 boggers, or maybe 38.5x11 bogger

Originally Posted by boydmick

I'm probably missing something here but. . . . . .

Isn't the stock LCA one of the major limiting factor for flex?
I think a Johny joint would help, but you're still only gonna get minimal rotation at the rear due to clearance at the bracket/arm interface.

The limiting factor for flex with the radius arm set up is that on one side the front bushing is pulling down and the other is pushing up, and since the axle isn't going to twist, it just binds in the bushings. Taking one bolt out of one side of the radius arm helps -

http://forum.ih8mud.com/showpost.php...72&postcount=5

The x-link or cranky link get's rid of this issue. The results of it are quite impressive -

http://www.dobbinengineering.com/index.htm

http://www.outerlimits4x4.com/phpBB2...ighlight=xlink

Thing with the x-link is that you have that big hunk of steel hanging out in front of the axle. It's probably not that much more likely to get hung up than the front axle itself, perhaps, but perhaps not. I like how using a johny joint in that direction keeps the forces on the bolt in shear rather than tension like the x-link seems to. Really, the V-link is just a different way of doing an x link on the backside of the axle rather than the front and still allowing for some caster adjustment if use a threaded johny joint.


Thought about going to a simple Y link, built off the stock radius arms. Heaps seem to get decient flex that way - though the top arms are usually angled toward the center of the axle pretty good.

We'll see, won't do anything for quite a while, but gotta think about something when your up till 3 in the morning downing codine cough medicine that just isn't cutting it...

Makes about as much sense as putting a 60 series body on an 80 series frame I guess....

[cruiserdan]

Originally Posted by ginericLC

Unless you are going bigger than 37s you aren't going to get a full bodied 80 much further down the trail than one on 35s. But what the heck do I know, I'm driving a 100 now.

That there is sig-line quality stuff............

[jon@svwbarchitects.c]

It you made the strait links or the radius bars the upper link and then used a Y link on the bottom, you would loose some ground clearance but could eliminate the track bar and would gain protection for the driveshaft.

[agent orange]

Originally Posted by Clutchee

You might wanta talk to Carl @ Outback Offroad Gear
His wifes 80 has a 3 link under the front it-did well at GSMTR this year.

I will say this, i watched that truck come up lower 2, and it didnt do any better than the leaf sprung trucks. In fact, dare i say it struggled?

[Nay]

Originally Posted by Walking Eagle

Why do it? Why not?

That is a question that always answers itself

Let me give you some Jeep perspective. Coil sprung Jeeps, with the now exception of the Unlimited, come with a short arm five link suspension. When highly lifted the control arms become very angled, which causes all kinds of problems on and offroad. A very common solution is the radius arm y-link.

The reason for this is the Jeep axles already have upper arm mounts, so it is a very simple redesign - you just need new "frame" mounts for the longer radius arms. Due to bushing size, you can get a ton of flex with just a johnny joint at the frame and rubber at the axle.

The problem with this approach is you are trading one set of problems for another. The long radius arms solve for the angle problem, but they introduce the unloading issue common to radius arm suspensions on steep climbs and create a substantial reduction in clearance due to arm mounting that is now behind the front tire and a hang up point.

80's have these issues out of the box, so most 80 owners don't have a sense of what it is like to not be constantly slamming around on suspension links and their low hanging mounts. Non-TJ Jeep owners have taken to radius arm mounts inside the subframe rails, limiting straps, and ultimately designs such as four linking to what I personally consider no real success other than "why not?".

I've watched people try it both ways, and the most successful approaches where there is a desire to retain the underlying vehicle design (you aren't going "Shortbus") always find creative ways to optimize the factory design.

An example I like to use in the XJ world is this rig. Instead of going long arm up front the owner raised the lower arm mounts to axle level and raised everything else up on a custom Ford Dana 44 front end, using a mid-arm 3-link. This suspension, outside of the 3-link that simply removes one upper arm, seeks to mimic the factory design while accounting for 7" of lift and maximizing clearance in every possible way.

In the rear, which on the XJ is a leaf suspension, there are still leaf springs. The pack is a longer boneyard Dodge spring with some leafs added with a relocated subframe mount on 2" blocks with a traction bar. A flat leaf spring can flex very well, and again, the underlying suspension design is not altered.

Both ends use the full travel of a 12" shock, and this rig is a suitable highway vehicle as well as one that runs trails like the Hammers. Notice how little damage for a rig that sees extremely difficult trails - means it isn't flopping all the time, so the platform is working extremely well, was extremely simple, and outside of the axle upgrades common to virtually any serious Jeep build, very inexpensive.

I like the comparison to the 80 because in both cases a lot of performance comes from keeping one end of the suspension focused on stability - it's just opposite ends between the two vehicles. XJ's are much easier to lift to 6" than say ZJ's/WJ's because of the rear leaf/front coil design - I think the 80 can be run on 6" of lift for the exact same reason and would personally be very wary of freeing up both ends to a point of unrestricted motion.

The other approach involves things like four linking, and those owners have spent a fortune and unimaginable amounts of time trying to dial in a suspension that doesn't fundamentally do anything more than the example above except have weird quirks in certain situations and a bunch of asking new questions to your "why not?" answers on forums like Pirate.

If you are not going to get rid of the 80's radius arms, you will not have solved for the bigger complications of those arms (suspension dynamics on steep ledge climbs and clearance), but you may unbalance the vehicle.

It is unsexy to take the simple approach. If you plan to keep the radius arms, simply beefing up the axle mounts and going "poor man's" 3-link will give a necessary increase in front flex without introducing any other unknown variables. If you add to this a well designed limited strap to keep the front end from dropping out and unloading, you will have a solution that a) minimizes cost and complexity, b) does not introduce unknown variables, and c) recognizes and leverages Toyota's intentional design to keep the front end stable on a rig as large and heavy as an 80.

Now, I still think you should do it, because I love to see the answers to "why not?" I'd love to muck around with an 80, although I'd do a mid-arm 3 link front and a rear leaf spring suspension. Of course, my "why nots" are easy: money, time, and I already have a rig that does everything I need it to do with no additional modification.

[Walking Eagle]

Originally Posted by agent orange

I will say this, i watched that truck come up lower 2, and it didnt do any better than the leaf sprung trucks. In fact, dare i say it struggled?

Leaf sprung trucks can flex great. I got more flex out of longer shackels and add a leafs onto what I think was stock springs on my 40 - sprung under even - still could bottom and max out a 14" shock.

Trying to twist the front of this 80 I can get maybe 6" extension on one side with the tire in the air and the other side sitting on the bumpstop.

http://forum.ih8mud.com/80-series-tech/163530-flexed-till-springs-popped-out.html

http://forum.ih8mud.com/80-series-tech/162864-extended-shock-towers-14-rancho-9000xls.html

[Walking Eagle]

Originally Posted by Nay

I've watched people try it both ways, and the most successful approaches where there is a desire to retain the underlying vehicle design (you aren't going "Shortbus") always find creative ways to optimize the factory design.

Shortbus is still radius arm, which is why it's body is tilted so much relative to the amount of axle movement on this 3 link 80. Which one do you think feels more like it's ready to tip?

[Walking Eagle]

Originally Posted by Nay

It is unsexy to take the simple approach. If you plan to keep the radius arms, simply beefing up the axle mounts and going "poor man's" 3-link will give a necessary increase in front flex without introducing any other unknown variables. If you add to this a well designed limited strap to keep the front end from dropping out and unloading, you will have a solution that a) minimizes cost and complexity, b) does not introduce unknown variables, and c) recognizes and leverages Toyota's intentional design to keep the front end stable on a rig as large and heavy as an 80.

Just how different do you really think a 'poor man's 3-link' (a term I've never liked since it really doesn't describe what's being done) is from an X-link, or the V-link?

Poor man's 3 link

- 2 radius arms
- Back of axle is mounted to both radius arms
- One mount on front of axle to prevent rotation

X- link

- 2 radius arms
- Back of axle is mounted to both radius arms
- One mount on front of axle to prevent rotation

X- link is just a sofisticated man's poor man's 3-link (say that five times fast) The V-link, is just a different take on the X-link trying to get adjustable caster, and hide the link behind the axle as much as possible.