look at thesae 2 set ups, which is better for a sammie rockcrawler? I will be going to coils near the end of my frame and streching the WB to aprox 103" from 89", so by going link and coils, I don't have top erxtend the frame and should have a 90* departure angle to boot. I'm still confused as to the links, I see one triangleated and the other not. I'm leaning towards triangledated, outside links on top of the tubes, going sch80 1.75" aprox pipe.

:D

:smokin:

Originally posted by SeaBass44
:D


The red one would be great if your building a monster truck

Mudtruck (first one) built his for mud. He didn't do so well in the rocks at TTC. The other was built for rocks. It's triangulated. Go figure:rolleyes:


:flipoff2:


Why don't ya find the god of suspension thread and ask a couple questions on it:D That'll make everyone happy.

Really, though. From what I've seen, double triangulated 4 links with opposing V's work the best. Like desertoy's.
But I like simplicity. I like leafs. Just don't like the approach/departure angles...but the 38.5 SX's will help a little:smokin:

I think what you're missing on mudtruck44's rig is a panhard bar??? Which the triangulated link setup eliminates the need for. I'd go with DOM for the links. I just don't like the idea of using pipe.

-Ummm, but to answer your q, tri

a 3 link is better then any 4 link
it is a truly no bind suspension
the 4link will always fight itself when twisted, even worse when triangulated
it will work but a 3 link is without the bind so why use the extra link

Originally posted by mj
a 3 link is better then any 4 link
it is a truly no bind suspension
the 4link will always fight itself when twisted, even worse when triangulated
it will work but a 3 link is without the bind so why use the extra link

Please explain how a 4 link "will always fight itself when twisted, even worse when triangulated"
I am trying to figure out if you are a total MORON who speaks with thinking or if you know something that EVERYONE on this board who has tried and tested 3 links doesn't know.:rolleyes: :rolleyes: :rolleyes:

Originally posted by mj
a 3 link is better then any 4 link
it is a truly no bind suspension
the 4link will always fight itself when twisted, even worse when triangulated
it will work but a 3 link is without the bind so why use the extra link

ok are the 2 links on the outside stright or triangleated? and from which end should the wide side be:D

Originally posted by Im4yotas

But I like simplicity. I like leafs.

I do too.............but............did ya read why I want to go link? bawaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa no frame ext with the links, that god of sus thread hurt my head!

OK, Here's what I came up with when I was researching this subject.
The standard 3 link doesn't work for rock crawling because:
1. When articulated, instead of articulating the axle under the center of the vehicle, it forces the vehicle to fall to one side or the other because of the single attachment point at the top center of the axle. I think this is called roll center. (does that make sence?)
2. Because the lower arms are connected from the outside of the axle housing to the outside of the frame, when you articulate the suspension, the side that drops will tend to push the vehicle over on it's side because the lower link arm on that side is pushing up on the outside of the frame where it is attached. This has proven to be the biggest problem with rigs that have standard 3 link in the rear. They are fun to watch because they ALWAYS have one front tire 3 feet in the air.
3. You end up with a serious rear steer problem.

If you go to a 4-link design and triangulate the lower links from the outside of the axle housing to the center, under the transfer case yoke. and the upper links from the outside of the axle housing to the outside of the frame. This will cure your rear stear problem and will not tend to push the vehicle over when articulated. (Works really good)

If you go with the dual triangulated 4-link design you get the advantages of the above 4-link and also it spreads out the side loads to all 4 link arms (rather than 2 on the other design)so that is doesn't tend to pull the link arm mounts out of the frame or break heim joints.

I use 1 1/2"x.120 wall mild steel tubing on my upper link arms ans 1 1/4" scedule 80 pipe for my lower link arms. They are all 4 the same length so I only have to carry one spare(though I have never used it).

I'm in the process of finishing my rear coils and links. Mine are like the bottom pic but my top links will come together into one heim at the diff so it will look like a Y on the top and an upside down V on the bottom so they cross. It is all 2"x.250 DOM. You can get it at All Metals there in Oroville for $6.17 a foot or from Valley Steel in Chico on Nord just past Phil's shop for $5.13 a foot.

The bottom links use Wrangler bushings on the axle end and Bronco radius arm ends on the cross member end. Mike Ladd sells some radius end extensions that fit inside the DOM. The top links will have Wrangler bushings on the frame end and a huge 1" heim on the axle end. I HOPE it all works out ;)

YOu gotta go trianglated 4-link bass! DO it like desertoy was talking about, where you have all four links triangulated to spread the load better. I have mine set up like a "W" formation and it works freekin awesome. AS for the other guy who says 4-links always work against themselves, well, your retarded:flipoff2: I can show you some pics of mine if want em

Originally posted by nuttzack
YOu gotta go trianglated 4-link bass! DO it like desertoy was talking about, where you have all four links triangulated to spread the load better. I have mine set up like a "W" formation and it works freekin awesome. AS for the other guy who says 4-links always work against themselves, well, your retarded:flipoff2: I can show you some pics of mine if want em

10-4:D but hey sure the "other guy" is a PCE not retarded;) lol, thx Desert Toy and Nutt, like I said later, just wanted tio get a good idea of the working of it, I never paid a whole lot of ATT: to it before..........I like the 4 equal length so I spare deal too:)

gotta say I didn't think MUDTRUCK would flex like it did!

http://www.rivercityrockcrawlers.com/TrailReports/TTC2002/TTC_204.jpg

I like his drop out coil thing too..

Originally posted by Curtis
Mine are like the bottom pic but my top links will come together into one heim at the diff so it will look like a Y on the top and an upside down V on the bottom so they cross.


You had better check this design because I think it might bind. I don't think you can use an "A" frame on the top and triangulated lower links. I think the roll center tendencies will fight each other.

a local guy swore up and down on how much the XX 4-link would bind and suck and break and suck and not work and suck and blah blah blah. we did it anyway and it rocks. desertoy is on the ball on this topic.

that is the coolest setup and it flexes like crazy and it still works. little to no rear stear, no axle bounce, it's just awesome. not just some ramp queen setup.

This design does flex well but for rock crawling it will put ALOT of force on the panard mount and eventually it would fail (blue circle)
Also, this is a perfict example of what I was explaining about the lower arms wanting to push the vehicle over when articulated.(yellow circle) because of the angle of the link arms and the fact that they are mounted to the oudside of the frame. It will push up on the frame where it is mounted instead of foreward.

OK, what about all of these comp rigs that are running the 3 links. They don't seem to have any problems. I have seen them work in person. Unbelievable if done right. Jason Paule, Tracy Jordan, Don Robbins, and Shupe all run the same design. Doesn't seem to want to tip their rigs over. I don't know, maybe I'm missing something. What is your take on this.

Erin

Originally posted by desertoy
This design does flex well but for rock crawling it will put ALOT of force on the panard mount and eventually it would fail (blue circle)
Also, this is a perfict example of what I was explaining about the lower arms wanting to push the vehicle over when articulated.(yellow circle) because of the angle of the link arms and the fact that they are mounted to the oudside of the frame. It will push up on the frame where it is mounted instead of foreward.

First, yeah there is A LOT of stress on the panhard mount. That is why the front looks like this-
http://www.mudtruk.com/hill.jpg
I have a brace going to the panhard bar mount.

About the angle of my bars, you realize the axle is drooped like a couple feet? The angle is not very steep normally so it doesn't really push up on the frame.

4-link won't really bind if the bars are parallel. The other secret to my flex is the long bars. I think it could work pretty well in a Sammy but triangulated bar or bars may be best.

Here is an idea I thought of the other day at work. I am a mechanic and at work we replace a lot of track bars on Dodge trucks. I was looking at them and realized how great they would work for suspension links. One end has a ball joint (the end that goes bad). The other end has a rubber bushing. They are made from solid bar close to an inch and a half. If you cut the usable portion off, you have almost 2' with a bushing on the end. Schedule 40, 1 1/2 pipe slides right over it tight. Cut two bars in half, splice em, and you have bulletproof bars! And the cost? go to your local Chrysler dealer and I am sure they have ten in the junk pile that you can get for almost nothing.

Originally posted by desertoy


You had better check this design because I think it might bind. I don't think you can use an "A" frame on the top and triangulated lower links. I think the roll center tendencies will fight each other.

Hmmm...I see what you mean (another good reason to talk about things here before actually doing them). I was hoping the big heim on the diff would make up for it, but I imagine it would put alot of stress on that one heim.

Since I haven't even cut the upper links yet, I'll have to look into doing it like the second pic Darren posted. It would be simple to change the design now instead of later ;)

Oh . . . I had thought about putting a radius arm end and bushing at the end of the A over the diff, but I understand these things placed there need replacing VERY often due to the torque placed on the one bushing. It is supposed to work great to allow a better roll than a heim, but I just didn't like the idea of replacing a bushing all the time.

Originally posted by desertoy
OK, Here's what I came up with when I was researching this subject.
The standard 3 link doesn't work for rock crawling because:


:eek: Then someone needs to tell these guys!!!

Mark's rig is 3 link front and rear. I'll let you tell him it's not a good rock crawler....... :rolleyes:

I've seen a lot of junk and a lot of very cool stuff. Even some of the junk work better than leafs. The key is arm LENGTH! If you get the arms too short, :nuke: . As long as the arms are long enough, it's a LOT more forgiving to everything else in your design.

desert toy,

please explain more about the roll centers fighting each other, as I have just finished my upper A-arm and lower triangulated links.
thanks

Lets hear it for the "Dumb Okies" with our overgrown non functioning junk, that always manage to do everything we "can't do" and fit where we "can't fit".

Any link suspension with half a thought given to geometry will work awesome as long as the arms are long enough. If the arms are long enough axle steering under flex is not an issue and the axle is very predictable and controlled. The arms on Mark Hansens mutt are almost 4' long so they are almost straight and the sombeach flat works.

Originally posted by YELLER BLAZER
The arms on Mark Hansens mutt are almost 4' long so they are almost straight and the sombeach flat works.

Those rigs are fawking huge. It would be a bitch to wheel those things on a tight trail, so guys that run the tight trails have smaller rigs and have more limitations on link placement. Also design imperfections are going to be more noticable with a shorter link than a long link, trying to get similar travel.

Originally posted by zags
Just for the sake of discussion, anyone see a problem with
all four links like this? /_\ (top view)

Gonna run a panhard bar? You don't get lateral stability with all links triangulated.

Depending on your angles and length, axle steer/shift might be exagerated..... The track bar would make that more complicated to predict as well...

is that a panhard bar or the axle?
if it's the axle then yes I see problems
the axle would not be located laterally

Just for the sake of discussion, anyone see a problem with
all four links like this? /_\ (top view)

oops, sorry, I was editing. it is the axle, with the links triangulated, it should locate the axle, no?

no

o.k. I see. duhhhh

okcrawler and YELLER BLAZER
You are correct, a 3 link will WORK. But so will a stock leaf spring setup. We are talking about pushing the suspesion geometry to its limits, and though a 3 link does get the job done, a properly configured 4 link will get it done more efficently. Just because a guy has a suspension setup that he runs in ARCA doesn't mean that it is the end all/ be all of suspensions. This sport is evolving by the day, and as people try different configurations, better ideas are going to surface. This just happens to be one of them.

I DO consider you guys to be "Dumb Okie Fawks" As do I consider myself (My family is from okmulgy Oklahoma). I am a firm believer that most good ideas come from under a big shade tree in someones back yard.

fcfred, I am not sure that my conserns are true reguarding that configuration. That would be a concern that I would check out though. Just mock it up without any springs and see if it binds.

I wouldn't say that long links are the solution to a untested crapily though out and simply bad design of a 4 or 3 link suspension, although they are gonna make your set up work much, much better. I have a sammi and all the links are between 41-45" long and I wouldn't go any shorter. Its flat dumb to say that as long as your links are long then your suspension will work. As I said, thats a big important part, but it's a little more complex than that to make them work right.

Seabass, whatever you do, make the links long and make the uppers and lowers as parrallel as possible. Also, try mounting the links on top of the axle, you'll be much happier with the end results!

Is the 3 vs 4 link idea the same for a 1/4 elip suspension?

Because the springs are hard mounted on one end does this slow the rear steer down a little?

And if you used a 3 link on a 1/4, would you bring all three links to the center of the vehicle (or close to) where they mounted to the frame?

I run wristed radius arms (sorta a three link) on both ends of the Mantis. Works well, controls wrap, minimal roll steer, etc. Links are 36" long.

The debate to me, is whether you want the axle to move sideways when it drops, or if you want it to stay dead-center all the time. With Mudtruk's setup, you have to run a track bar. Same with mine. That's the only thing that keeps the axle located laterally--the arms don't do it on their own.

With Camo's setup pictured, there's no need for a track bar, 'cause the triangulated links do the job, as they fight each other. On twist, it works--the only time they're fighting each other is when you try to push the axle sideways in the rig. No triangulation, you'll need a track bar.

As for W, XX, Y, or other style of linkage, it's up to you and your clearance issues. I did radius arms because it let me not move the gas tank.

Incidentally, my rig should, under load and climbing, flop onto the driver's side... strangely enough, every time it's rolled, it's been either endover backwards, or onto the right side.

The linkage that looks like /_\ would work (assuming the _ is a track bar, not the axle) but it would tend to bind a bit towards the upper and lower limits of vertical travel. Should twist well.

Ok, let's settle this once and for all. I've argued too many times about the issues with mounting lower control arms above the CL of the axle. So, here's an example to demonstrate my point…..

In the attached pic, you have three examples.
A - Upper control arms mounted 6" above axle, lower 2" BELOW axle.
B - Upper control arms still 6" above, lower mounted on center line of axle.
C - Upper control arms still 6" above, lower control arms 2" ABOVE axle.

Now we dig out the statics 101 book and run a few numbers. Figure on 20,000 foot lbs of torque (that's 200 ft-lbs of torque thru that 100:1 gearing many of you have).

Calculating for the force on the top control arm(s) F1.

A - F1*6 + F2*2 = 20,000 F1=6/2F2 ….. F1 = 1,700 lbs
B - F1*6 = 20,000 ….. F1 = 3,300 lbs
C - F1*6 - F2*2 = 20,000 F1=4/2F2 … F1 = 10,000 lbs

Then, someone decides to use 3/4" heim joints all round…:nuke:
Are you starting to get the picture now?

These numbers ONLY account for toruqe. They don't support the weight of the vehicle or the bouncing/shock loads going on!

Sure, you had to go and get the statics going didn't you. I am trying not to use this style of design. Just go with what I think works:flipoff2: . Those 5 yrs in engineering school can't help.

Erin

This non-engineer type need a little help. Is the load from F1 spread over the 4 upper heim joints? At a 20k rating each (for good chromo ones) will the two links only support 20K or will
they support 40k?

Have you taken a look at the thread twistedmetal posted about a week back? http://www.pirate4x4.com/forum/showthread.php?s=&threadid=66343

Well, no duh on the torque load shit. I dont think this was the direction in which this thread was intended and nor did I wan't to sit here and argue, but thanks for the figures for thos who want and need them or had no idea about link placement and spacing, but let me say one thing about your examples and something you failed to mention. PUT YOUR UPPERS HIGHER FOR MORE SPREAD AND YOUR TORQUE LOAD FIGURES CAN GO RIGHT DOWN THE TOILET! Not really, but you get it! DO what you want bass, but I'm telling ya it's nice having those links outa the way of things and also you will have much less angle on the links. I'm done before this gets ugly:D

Originally posted by okcrawler
Ok, let's settle this once and for all. I've argued too many times about the issues with mounting lower control arms above the CL of the axle. So, here's an example to demonstrate my point…..

In the attached pic, you have three examples.
A - Upper control arms mounted 6" above axle, lower 2" BELOW axle.
B - Upper control arms still 6" above, lower mounted on center line of axle.
C - Upper control arms still 6" above, lower control arms 2" ABOVE axle.

Now we dig out the statics 101 book and run a few numbers. Figure on 20,000 foot lbs of torque (that's 200 ft-lbs of torque thru that 100:1 gearing many of you have).

Calculating for the force on the top control arm(s) F1.

A - F1*6 + F2*2 = 20,000 F1=6/2F2 ….. F1 = 1,700 lbs
B - F1*6 = 20,000 ….. F1 = 3,300 lbs
C - F1*6 - F2*2 = 20,000 F1=4/2F2 … F1 = 10,000 lbs

Then, someone decides to use 3/4" heim joints all round…:nuke:
Are you starting to get the picture now?

These numbers ONLY account for toruqe. They don't support the weight of the vehicle or the bouncing/shock loads going on!

Well that is a very impressive group of numbers. The reason people like me mount both links above the centerline of the axle is to improve the anti-squat characteristics. By mounting them on the top, it keeps the links at level to the ground as possible. My rear 4 link setup would be in your "C" catagory. My lower is approx. 2.5" above the centerline of the axle and the upper links are 9.5" above the centerline of the axle. My link arms are about 42" long and are in a dual triangulation configuration. I run 3/4" heims with spacers that reduce it down to a 1/2" bolt. Please run these numbers and we'll see how it comes out on paper.
In the real world it works great. I have had it almost a year now and have run some pretty hard trails including 2 CalRocs events with absolutly no problems what so ever. Here is the only picture I have at work.

Heims are the :nuke: , I agree:D Are your links almost flat desertoy?

Originally posted by nuttzack
Heims are the :nuke: , I agree:D Are your links almost flat desertoy?

At ride height they are.

and with all of your power and gear multiplication have you ever :nuke: any heims? You run greasable heims don't you?

http://www.olywa.net/rdsrfr/4link.html

Originally posted by nuttzack
and with all of your power and gear multiplication have you ever :nuke: any heims? You run greasable heims don't you?

The only problem I have had with my heims is where the ball and race is pressed into the housing of the heim, it wants to slide out. I just tack weld them and the problem goes away. Mine are greasable but I never grease them.
Now that I am home here is a couple of pics of my rear suspension.

Front mount

this may be a dumb question, but how did you get your springs so flat?

I'm using F250 springs for my 1/4 ellip setup and I took one leaf out. The springs sit completely flat and have even started to sag farther. On anything other than a lightweight buggy I would recomend using all the leafs in the original pack. I might even add another leaf to the new springs I just got. By the way I have a pretty standard CJ-7(It's not all tubed).

and you refer to ME as the moron!

OK, Here's what I came up with when I was researching this subject.
The standard 3 link doesn't work for rock crawling because:
1. When articulated, instead of articulating the axle under the center of the vehicle, it forces the vehicle to fall to one side or the other because of the single attachment point at the top center of the axle. I think this is called roll center. (does that make sence?)

you are talking wishbone version of a 3 link, good choice, not really standard at all though
first that point would be EXACTLY dead centre of the vehicle at all times
second that point should be mounted at the chassis end to try and raise the roll centre up for a more stable feel

2. Because the lower arms are connected from the outside of the axle housing to the outside of the frame, when you articulate the suspension, the side that drops will tend to push the vehicle over on it's side because the lower link arm on that side is pushing up on the outside of the frame where it is attached. This has proven to be the biggest problem with rigs that have standard 3 link in the rear. They are fun to watch because they ALWAYS have one front tire 3 feet in the air.

so why do the lower arms HAVE to be the 2 straight ones? why cant those be the uppers? not that I agree with your theory and how does this differ at all from a standard triangulated 4 link???

3. You end up with a serious rear steer problem.

If you go to a 4-link design and triangulate the lower links from the outside of the axle housing to the center, under the transfer case yoke. and the upper links from the outside of the axle housing to the outside of the frame. This will cure your rear stear problem and will not tend to push the vehicle over when articulated. (Works really good)

other then the links must deflect to allow the suspension to 'articulate'(I prefer the term roll) due to the arcs the links travel in fighting one another

If you go with the dual triangulated 4-link design you get the advantages of the above 4-link and also it spreads out the side loads to all 4 link arms (rather than 2 on the other design)so that is doesn't tend to pull the link arm mounts out of the frame or break heim joints.

so why is it that you couldnt run a wishbone and 2 triangulated links to remove the bind and have the exact same roll characteristics but without the built in binding of a 4 link?

I use 1 1/2"x.120 wall mild steel tubing on my upper link arms ans 1 1/4" scedule 80 pipe for my lower link arms. They are all 4 the same length so I only have to carry one spare(though I have never used it).

how much force does it take to roll the suspension from one side to the other. the links fight each other kinda why every race vehicle is going 3 link these days

now to read the rest of the thread

You had better check this design because I think it might bind. I don't think you can use an "A" frame on the top and triangulated lower links. I think the roll center tendencies will fight each other.

I didnt get far before you said another moron statement.
maybe you should look up what a roll centre is then read what you posted but substitute the phrase 'roll centre tendencies' with '2 axle locating devices' and then you will have EXACTLY what I am stating is happening in your triangulated 4 link thing.
in order for it to move something is deflecting.
his wishbone idea kills your 4 link.
I can send you to a real good board to educate you on triangulated 4 link but they are real mean not soft like pirate4x4.
just tell them it is on a car and watch the flames (http://corner-carvers.com/forums/forumdisplay.php?forumid=7)
post it something like ' a 4link with both upper and lower links triangulated will roll more freely then a 3 link'

http://www.olywa.net/rdsrfr/4link.html

this link is full of shitte, all bad info
he uses sedan 4 links as an example but fails to notice the massive rubber bushings that need to be run to allow the suspension to work.

Originally posted by mj
other then the links must deflect to allow the suspension to 'articulate'(I prefer the term roll) due to the arcs the links travel in fighting one another
Won't the axle simply rotate (like if you went and turned the pinion up - that kind of rotation) if the upper links travel in a different arc than the lower links?

Isn't this the whole reason for mounting links at a location near the output of the transfer case? If you read the thread I linked to in my previous post, frankie posted extensively about a reverse 4-link design he uses in the buggies he builds which keeps the pinion pointed at the t-case output throughout the axle's travel. And it's held up to 2.5-ton rockwells and 44" cut boggers quite well so far. Take a look at that thread.

It just seems to me that you are assuming that the axle will simply stay at a constant pinion angle throughout it's travel. In most of the link suspensions I've seen, it moves quite a bit. Correct me if I'm wrong, but it looks like that's what you're assuming. Can you be more specific on what you state is binding? The only thing which should be binding is the two triangulated arms against each other, when the axle is forced sideways. The upper and lower links traveling in different arcs will simply cause the axle to rotate.

jesus fucing chriminy, this post is going exactly where I thought it was going. NOWHERE, but a bunch of fucking technical babling, which could be fully dug up if you want to use the little search f unction

Originally posted by nuttzack
jesus fucing chriminy, this post is going exactly where I thought it was going. NOWHERE, but a bunch of fucking technical babling, which could be fully dug up if you want to use the little search f unction

I think this thread is EXACTLY what seabass44 needs to know. Everyone has an opinion, and everyone says the other person did it wrong. At the same time, the guy that 'did it wrong' is happy as sh!t with what he built!

So, it's not fawking rocket science!

Make up a plan, build it STRONG, and enjoy! It does not have to be perfect, just reliable…..

Seabass44 - My personal recommendations for your design:
1 - Lower arm mount should be just below CL of the axle to reduce stress on the joints and mounts.
2 - Parallel arms (and long arms) will eliminate torque lift (aka anti squat).
3 - Make the arms as long as possible, this makes everything more forgiving.
4 - Johnny joints and spring bushings over heim joints!

Desertoy - For your geometry, the upper arms would see a load of: F1= torque/2.5 (assuming 20,000 ft-lbs F1 = 8,000). The 9-1/2" upper mounts make yours possible. Getting 9-1/2" with a fuel tank above you axle is much harder to do for those not building a tube buggy! Another example, what works for someone does not work for everyone…..

Ok Crawler, you nailed it!

Originally posted by mj
http://www.olywa.net/rdsrfr/4link.html

this link is full of shitte, all bad info
he uses sedan 4 links as an example but fails to notice the massive rubber bushings that need to be run to allow the suspension to work.



What are you talking about? The suspension described in that link
is used by most drag racers. I dont have alot of experience yet with 4wd four links yet, but I do have alot of experience with that type of 4 linkand have the trophys to prove it. All of them are heim joint suspensions that articulate quite well and move quite freely. It looks to me like you have nothing from practical experience to add, just critisizing other's practical observations. Another engineering student maybe?

1st thanks to everyone that replied! I think I know 1/2 way what I will do:flipoff2: heims=NO, JJ's=NO...cheap ass tractor joints that I see on the trail working all the time=YES:flipoff2: I saw one of the SRC gang in his sammy with tractor joints, worked great, full hydro he had worked great too;) he thought the 1.6 swap he did was a turd and underpowered:confused: trail only, still said not enough power:p :p BB maybe:usa: lol

Originally posted by SeaBass44
1st thanks to everyone that replied! I think I know 1/2 way what I will do:flipoff2: heims=NO, JJ's=NO...cheap ass tractor joints that I see on the trail working all the time=YES:flipoff2: I saw one of the SRC gang in his sammy with tractor joints, worked great, full hydro he had worked great too;) he thought the 1.6 swap he did was a turd and underpowered:confused: trail only, still said not enough power:p :p BB maybe:usa: lol

Seabass....I have the 16v conversion....It is well worth it!!!

Originally posted by mj
http://www.olywa.net/rdsrfr/4link.html

this link is full of shitte, all bad info
he uses sedan 4 links as an example but fails to notice the massive rubber bushings that need to be run to allow the suspension to work.

Hey I only posted that because he explains the movement of the four link well. not that it completely applys.



http://www.allpar.com/ed/suv-suspensions.html

this guy acctual designs and builds link suspensions for the the big 3. his site has SOME usefull info.

Originally posted by SeaBass44
1st thanks to everyone that replied! I think I know 1/2 way what I will do:flipoff2: heims=NO, JJ's=NO...cheap ass tractor joints that I see on the trail working all the time=YES:flipoff2...

I know those, you can buy complete links with threaded ends at Atwoods (tractor 3pt). In fact, I welded one of those links this weekend for a Sami at Zookimelt. Snapped off where it is swaged down for the threads.. :p :)
They also make a nice clinking sound as they take up slop in the joint.. Oh well, everyone will know who is coming down the trial... ;) :D

What are you talking about? The suspension described in that link
is used by most drag racers. I dont have alot of experience yet with 4wd four links yet, but I do have alot of experience with that type of 4 linkand have the trophys to prove it. All of them are heim joint suspensions that articulate quite well and move quite freely.

you need to look at what the links are trying to do.
the 4th link is the problem.
if you set the length of the links as a constant and thier mounting points as a constant,
then roll the suspension, and measure the distances between the mounting points on the axle and the frame you will see that it cannot be done.
therefore something is deflecting to allow the motion.
could be why he is ripping the races from his rod ends?
drag race cars travel in a small range of motion and dont really care about roll bind, as evidensed by the fact that some still think a ladder bar is a good suspension design.
road racers that use solid rear axle have tossed the 4 link and gone 3 link to avoid the bind. they have very small suspension travel but want to be able to tune and control roll 100%.

easy test for someone that has a four link is to roll it to full lock and try and remove 1 link, or remove one link and roll it to see how far the link would be from bolting in.
if there is no bind or deflection it should fall right into place.
a Ford owner on here described the radius arm as using the axle as a swaybar, this also applies here IMO.

I am not a student or an engineer, I have just been trying to find the best suspension for my Mustang and 4x4 projects.
the three link is THE suspension configuration that is bind free.
the wishbone doesnt seem to work for the Mustang as you cannot package the rollcentre where it should be (though the car guys alway see the single attachment end at the dif and never consider it at the chassis end)

so far in 4x4 world it looks like the torque tube does everything you guys want but only the 'Moggers have it

Seabass, I ran the tractor joints for 3 yrs. There are a lot of benefits to them- cheap, indestructable, easy to work with.

I am no longer using them for my links though. After a while they were worn so bad that I actually started getting wheel hop. I don't know if you have talked to others using them, but find out how long they are lasting for them. They wear out quick for me but I think it may just be because of all the mud getting to them.

I liked the tractor joints but from now on I am using bushings wherever I can.

Originally posted by mudtruck44
Seabass, I ran the tractor joints for 3 yrs. There are a lot of benefits to them- cheap, indestructable, easy to work with.

I am no longer using them for my links though. After a while they were worn so bad that I actually started getting wheel hop. I don't know if you have talked to others using them, but find out how long they are lasting for them. They wear out quick for me but I think it may just be because of all the mud getting to them.

I liked the tractor joints but from now on I am using bushings wherever I can.


thanks:)

What would be the negatives of running Johnny joints? Are they strong enough?

You guys should really check out the thread I posted a few weeks back. Frankie Fountain joined in and we had a go. I finally gave up, went out into the garage and built an EXACT half scale replica of my rig. Solved all of my questions. Also, Frankie DOES know is shit.

I keep hearing about how 3-links shove the axle off to one side. Well, look at the new designs in this: the upper center joint is being mounted 10 inches or so off the top of the differentials! It NEEDS to be where the driveshaft is going-axle center line! On my front axle, my joint is mounted low, beneath the top of the differential. This will minimize deflection. I also came up with a custom front joint utilizing a spring bushing and a swivel mount. Cheap, beefy, and it is a captured joint, meaning I don't have to dig a pinion out of an oilpan!
The 4-links that ARE NOT triangulated DO have more bind than a 3 link or a triangulated 4-link. It doesn't allow the axle to rotate.

Seabass, Contact Frankie Fountain. He'll gladly chime in and help out as well, but I think you need to make a model. It will make you feel alot better, it will answer ALL your questions, and you will have figured it out on your own.

Originally posted by Im4yotas
What would be the negatives of running Johnny joints? Are they strong enough?
Yes and no. I think the new Rubicon Express joints are the hot ticket. The JJ's I have seen getting trashed are because they are being subjected to severe side loads and are poppingout the retaining clips. Here's a pic of what I did, but I don't know if it will work yet or not:

Originally posted by mj
and you refer to ME as the moron!


you are talking wishbone version of a 3 link, good choice, not really standard at all though
first that point would be EXACTLY dead centre of the vehicle at all times
second that point should be mounted at the chassis end to try and raise the roll centre up for a more stable feel


so why do the lower arms HAVE to be the 2 straight ones? why cant those be the uppers? not that I agree with your theory and how does this differ at all from a standard triangulated 4 link???


other then the links must deflect to allow the suspension to 'articulate'(I prefer the term roll) due to the arcs the links travel in fighting one another


so why is it that you couldnt run a wishbone and 2 triangulated links to remove the bind and have the exact same roll characteristics but without the built in binding of a 4 link?


how much force does it take to roll the suspension from one side to the other. the links fight each other kinda why every race vehicle is going 3 link these days



MJ, I am not sure where you are getting your information. BUT YOU ARE TOTALLY OFF BASE!
Every comment I have made is based on REAL LIFE EXPERIENCE. I have built these different suspension configurations and currently run a dual triangulated 4- link setup on my rig. I can assure you that there is absolutly no "bind" or "deflection" in my suspension because after I BUILT IT, and before I installed the springs. I RAN IT THROUGH ITS FULL RELM OF TRAVEL! I actually did this with my own 2 hands. Not on a piece of paper, not in my mind. I ACTUALLY DID THIS AND IT WORKS GREAT! So put down your school books, open your mind, pull your head out of your ass, and you will find that you are mistaken.
We are talking ROCK CRAWLING HERE, not drag racing, or off road racing, or any other racing. I understand where you are coming from because I have raced 1/4 mile (biult my own 4-link). I currently race a class 8 off road truck (just finished building my own wishbone 3-link with 23" of travel) BUT THIS IS NOT ROCK CRAWLING. You can't compare them because they are not comparable.
It pisses my off that you would mislead these people based on nothing but your misguided opinion SO STOP IT! Go out in your garage and learn for yourself like I did, and then come back with some usefull FACT BASED opinions.

I built a suspension model last weekend and did some mockups. I highly recomend this, I learned alot. Including; the body's roll center can change drastically depending on the link configuration.
triangulated top links(close together at frame) move the roll center to the point where the upper links attach to the frame. Triangulated lower links (close together at frame) move the roll center to the point where the lower links attach to the frame. the setup that desertoy uses (both upper and lower links triangulated) moves the roll center exactly between where the upper and lower mounts attach to the frame. links close together on the top of the axle only moves the roll center to the point on the axle where they are attached. this means the roll center also moves with suspension movement. Three links have the same behavior. As the axle rotates in articulation it seems to sweep through the arc, forcing the body to roll. It also causes massive rollsteer with one wheel drooped. With the wishbone of the three link at the frame end, the roll center of the body is high. It rotates at the point that the wishbone is attached. But it exagerated the sweeping motion of the rear axle in articulation unless the axle was at full bump. I think the the setup that desertoy uses is the best comprimise for a nice high roll center and reduced rollsteer.

Originally posted by zags
I built a suspension model last weekend and did some mockups. I highly recomend this, I learned alot.

any pics???????????

ok here are some progress pics
upper A-arm
lower semi-triangulated links
not completely triangulated due to Driveshaft clearances (offset driveshaft)
.25 2x2 square links about 42 inches long (too heav up top)
bushings at frame, Johny joints at axle
center A-arm axle bridge not complete
any input?

wtf!
everytime I try to post the pics it says problems with the server?!?!?

lets try again

Originally posted by fcfred
lets try again


looking good:) nice frame work, why square links?

I think square is stronger, we'll see.

Originally posted by fcfred
I think square is stronger, we'll see.

then why dosen't NASCAR use square cages?:p :p

All I have to say is wah wah.

Originally posted by mccombs07
All I have to say is wah wah.

o that was helpfull, thx for padding on my post newbie...try testing, you will over 100 in no time and will not look so useless padding there instead of on a serious post. thx again:flipoff2: :rolleyes:

Desertoy;
Like your setup, do you have a pic of the bumpstop to spring
config? Maybe its on one of the pic's and i missed it.
setup looks good though.

as for the square verses round issue
take a sledge and try it to a couple pieces of scrap
and see the results. I think the round would fair better than the square.

What a great thread! This has been much simpler to understand than that God of Suspension thread, that's for sure. I've got a couple of questions and confirmations for the design that seems to be the best:

CONFIRMATIONS

1) The top links should be wide at the frame and converge to the top of the axle, right?

2) The bottom links are as wide as possible on the axle and converge to just below the output on the transfer case, right?

3) The links should be mounted in such a way that they are parallel with each other and the ground when at rest, right?

4) Ideally, for clearance issues, the bottom links should at least be at or above the CL of the axle, right?

5) Ideally, the length of the arms should be all the same to prevent binding, maintain a proper roll axis, and make it easier for carrying spares, right?

QUESTIONS

1) What's the best joints to be used on the axle locations/frame-crossmember locations? Should they be different?

2) Does the distance between the two arms (at the converged end) effect the rear steer, etc? Should they be as close as possible?

3) If I have driveline or space issues with the above design, would there be a hige difference if I reversed the triangulation between the upper and lower arms? Would I get similar results?

That's all I can think of right now as I'm reading one of these other threads someone on here recommended to read too. Thanks a bunch for all the help,

Chris

I just got done reading this entire thread: http://www.pirate4x4.com/forum/showthread.php?s=&threadid=66343&perpage=25&pagenumber=1 and now I'm confused as to which is right for the bottom links. Should I coverge them to just below the transfer case yoke or keep them pretty close to parallel with the frame?

Chris

Here's some shots of mine from back when I was building it. I went double triangulated and above axle centerline for several reasons. Better geometry was the main, elimination of rear steer and ground clearance considerations were nice bonuses. I get about 1" of steer throughout the entire range of travel. I also don't get any bind. Desertoy was my inspiration when I built this thing. My lowers are 2.5" above the tube and the uppers are another 9" above that. All links are 40".
http://pics.montypics.com/onetonxj/2004-02-19/1077226619_sideview_top_rt.jpg
http://pics.montypics.com/onetonxj/2004-02-19/1077226730_rtside_4_link.jpg http://pics.montypics.com/onetonxj/2004-02-19/1077226685_sideview_rt.jpg http://pics.montypics.com/onetonxj/2004-02-19/1077226826_backview.jpg

Oh yeah, I run 2 piece 5/8-3/4 FK rod ends, no teflon junk in them. I have yet to have a problem with them and I've done some stupid shit too. Here's a shot of it out on the trail so you guys know that it's not a virtual heep like a lot of "experts" run.http://pics.montypics.com/onetonxj/2004-03-07/1078673318_PA080006.jpg

Originally posted by ravencr1
What a great thread! This has been much simpler to understand than that God of Suspension thread, that's for sure. I've got a couple of questions and confirmations for the design that seems to be the best:

CONFIRMATIONS

1) The top links should be wide at the frame and converge to the top of the axle, right?

2) The bottom links are as wide as possible on the axle and converge to just below the output on the transfer case, right?

3) The links should be mounted in such a way that they are parallel with each other and the ground when at rest, right?

4) Ideally, for clearance issues, the bottom links should at least be at or above the CL of the axle, right?

5) Ideally, the length of the arms should be all the same to prevent binding, maintain a proper roll axis, and make it easier for carrying spares, right?

QUESTIONS

1) What's the best joints to be used on the axle locations/frame-crossmember locations? Should they be different?

2) Does the distance between the two arms (at the converged end) effect the rear steer, etc? Should they be as close as possible?

3) If I have driveline or space issues with the above design, would there be a hige difference if I reversed the triangulation between the upper and lower arms? Would I get similar results?

That's all I can think of right now as I'm reading one of these other threads someone on here recommended to read too. Thanks a bunch for all the help,

Chris Does anyone have any answers or comments to my questions? I would love to know these things for sure.

Chris

1) What's the best joints to be used on the axle locations/frame-crossmember locations? Should they be different?

I like the Johnny Joint style because they are cheap and don't make noise. But its mostly a matter of personal preference.

2) Does the distance between the two arms (at the converged end) effect the rear steer, etc? Should they be as close as possible?

Uppers as close as possible at the axle. Lower set so that there project intersection is at the cg of the vehicle in the top view.

3) If I have driveline or space issues with the above design, would there be a hige difference if I reversed the triangulation between the upper and lower arms? Would I get similar results?

Don't see how you could have drive line clearance issues with this type of suspension.

Originally posted by Air Ride
1) What's the best joints to be used on the axle locations/frame-crossmember locations? Should they be different?

I like the Johnny Joint style because they are cheap and don't make noise. But its mostly a matter of personal preference.Where's the best place to get these style joints? Are they as durable and strong as the other types of joints? So is it safe to say that johnny joints should be used at every location then?2) Does the distance between the two arms (at the converged end) effect the rear steer, etc? Should they be as close as possible?

Uppers as close as possible at the axle. Lower set so that there project intersection is at the cg of the vehicle in the top view.As far as the uppers go, should the wide end be as far apart as possible too? In addition, how do I go about finding the CG of my vehicle to determine the distance between the converged(front) side? Should the lowers be as wide as possible on the axle too?

Thanks a lot for the help on this stuff,

Chris

All the good info that I have retained from link suspension came from THIS (http://www.pirate4x4.com/forum/showthread.php?s=&threadid=168577) thread. Goes into great detail about squat and anti squat, and the negatives and posatives, but still touches on most other points as well.

Originally posted by Air Ride
3) If I have driveline or space issues with the above design, would there be a hige difference if I reversed the triangulation between the upper and lower arms? Would I get similar results?

Don't see how you could have drive line clearance issues with this type of suspension.

And if you did it for some reason, you would definitely not get similar results. The roll axis would be very steep, which means you'd get a lot of axle steer. The roll center would be very low as well (more body roll, bad on side hills).

Thanks for the other link on 4-links. I'm going to read it right now!

Chris

Originally posted by ErikB


And if you did it for some reason, you would definitely not get similar results. The roll axis would be very steep, which means you'd get a lot of axle steer. The roll center would be very low as well (more body roll, bad on side hills).

1st off, I can't believe this dug out of the mud from 2 years ago!
But since it's here...

I am having my own personal battle with this right now. BUT, doesn't Avalanche Engineering run all their link configs this way? With straight uppers and tri'd lowers? I THINK Camo runs his rear setup this way, too. Maybe I missed the point, but I haven't heard any negs about their setups yet.
I ran a 3 link in the rear of my rig that is reversed and inverted, that is, the wishbone is on the botom and facing forward with the single joint mounted beneath the Tcase output. Between it and the front standard 3-link, it is basically undriveable, even WITH sway bars. Feels like a really tall skateboard, despite the fact that it hooks up with unbelievable success! It would be fine if I stayed in a parking lot and never had to turn....:(

Maybe I read it wrong, but when I wrote that I was thinking he was talking about a dual-tri setup and what would happen if it was reversed...

If its straight uppers and standard-tri lowers converging at the frame end, then sure- that can work.

mine was just finished up this weekend....brake lines and d-shaft install is all that's left....

35" arms, all equal length. AS calcuates to ~75%. Testing the 20th in Attica.

(pic is with the frame lifted and at near-full droop. Ride height with 38.5 tires is 23" to the bottom of the frame)

Looks like you need to mount your shocks too:flipoff2:

Now this is some sick flex, and I've never seen this type of design have you guys?

http://www.orp.com.au/Gigantor/Gigantor_page.htm

Chris

Hello
I was wondering what is wrong with using radius arms front and back. They would mimic the 3/4 ton ford 4x4 on the front and the old chevy pick ups on the rear. you would just have to use panard bars front and rear but it would be a lot simpler. You could mount 2 hiem joints 1 even with the axle tube and 1 above it and weld them together at the hiem joint that connects to the frame bracket and then put a triangle type webbing inbetween them to futher reinforce them. You would have to conect them to the frame for the rear diff at the front u-joint and on the front diff. at the rear u-joint. Tell me if you think this will work because I am thinking of taking a ford ranger 2x4 and making it 4x4 with coil overs
Rick in Enid Okla.