4 Link or Radius arm/Front

[FROADER]

Are those trucks street driven? I mean, DD type driven, not the occasional parade duty

They can easily pull DD duty.

 

[Turdle]

They can easily pull DD duty.

Could, and Do, are different here. We need to determine the proper axle setup for a daily driven , trail usage truck.

Not to be difficult, but I have been looking. The above trucks cannot be used as a daily driven reference. IMO

 

[rookieshooter]

Are those trucks street driven? I mean, DD type driven, not the occasional parade duty

That's the problem I'm having. I think Ricks is hard core type stuff, trails only. I don't know about the other. What ever one I use has to be safe and handles well on interstates. Safe over rides all else.

But I'll use the best hardware and heavy tubing that I can find. And I have confidence in my welding also.

 

[DB_1]

Yeah, i'd say Tom's (FAKRWEE) truck could do DD quite well, he drives out to the trails in the rig quite often, other than that it get flat towed so it has to be somewhat streetable.

Rick's i'd say would be iffy only because of his wheel/tire combo, he's on beadlocks so I don't think the tires are balanced but maybe he can chime in on that.

 

[FROADER]

Rick and Tom's are more stable than mine...

By they could, I meant that if they didn't have other vehicles to DD they would be just fine to DD.

Mine isn't the best DD because (like Dave mentioned) the tires are bias ply unbalanced off-road tires. You put more streetable tires on mine or Rick's, you could put 50k miles a year on it.

Actually like Burns does...

 

[rookieshooter]

This post is getting like a lot of the other sites regarding 3,4,5,links triangulated, parallel and all the other nomenclature used in axle suspension systems. Sometimes it gets a little overwhelming. Sure does make for a good Read.

 

[rookieshooter]

Thanks Froader for being so forthcoming. That helps a lot.

 

[Turdle]

I think the desired level of street worthiness -Off road ability is important also. Just like building an engine, it is important to be honest with yourself in what you want.

Since my goal includes 800+ mile one way driving, with adjustable ride quality for the bumpy stuff, I am swayed to the opinion thinking that for street manners AND off roading combined, the best result would be to use the stock components from the original combination , and modify them for a bit more flex.

However, I have to admit I have quite a bit of studying to do yet.

 

[FROADER]

As you know rookie (with your drag experience) you build the characteristics into the suspension design. You can make it act however you want it to.

All those 4-link terms like: anti-squat (accelerating), anti-dive (braking), instance center (exact spot your power/braking is being directed), roll and pitch, mean you make it do what you want.

 

[rookieshooter]

A big thumbs up on that one. That brings back flashbacks of my first built traction bars in the late 60s. Yep, I'm just that young

 

[james t]

General thoughts-

The advantage of radius arms is simplicity. There are no measurements to mess up. No worries of 8 tons of calculations, hours working it on jackstands making sure links wont bind and angles are correct. Radius arms are the dummy way to go. Extended or wristed, they can flex awesome and ride great on the street.

The advantage of a link setup is tuneability and being able to go fast(ish). If you want a rock crawler that can also blast through the ruff stuff then a link setup is the way to go. You can also get the same or better flex as radius arms with shorter links, and mounted outside the framerails to keep a taller belly height than you could ever get with extended radius arms.

Ride quality and dailydriver ability will depend on tire/wheel combo... radius arms or links both equally make a good DD. Springs and shocks also affect this, but just about any type of coil, shock, coilover etc. that works good in the rocks is going to ride decent on the street... with certain applications of airshocks excluded. I daily drive mine whenever im not on the bike and even with no swaybars its fine on the street (grumpy transmission notwithstanding).

 

[RockRanger]

How much actual lift do you have or want ? I have about 5" of lift with my 3 link front setup. I just don't see a SAS working with much less lift and having much up travel. It works damn well. Stiffer shocks and some balanced tires and it could be daily driven. I will drive it out to day runs so I don't have to mess with the trailer. We are setting up 90ranajo with basically a copy of how mine is setup except with coil overs and a full width axle. Not sure you can get much better side hilling then mine does.

 

[dkchrist]

One other note on radius arms, you must insure the mounts are substantial as this this the main connection to the frame. This is another advantage of the 4 link is it will distribute the forces to more places on the frame.

 

[rookieshooter]

Rockranger, If not 5" it's very close. Could still raise a little more with the coils. But problem now, if any higher I can't get into the garage with the roof cage on nothin I can't take off though.

dkchrist, I gave a lot of thought to that when I did my rear radius arms in regards to being substantial enough.

Here is the rear axle bracket I built for the frame mount. I don't think it's overkill buy any means. Could even weld it to frame. But I think I have enough shear strength in the bolts. Of course the bushing is double sheared mounted. And where it is located is where the original body mount used to be, so I also designed it to funtion as a body mount also.

If I go the 4 link then all four connecting links will be built using 1.75 x .250 wall tubing and using the Ballistic joints at frame end, like I did in the rear radius arms.

Four of these type front axle connecting links to frame would really give me confidence in going down the interstate.

 

[rookieshooter]

Your up early James, that's good stuff you posted.
This is just too much info for me to consume this rainy morning. Packing up the Bronco and going Trout fishing for a few hours. Need to cleanse my brain of all this geometrical stuff. And I thougt the rear was tuff.

 

[rookieshooter]

Seems so far that the consensus is...that if you build it strong enough and safe enough that a 4 link will work fine as a DD. The main reason I need to which way I'm heading with this is that I have not ordered all the hardware and no tubing yet. Obviously I have to make my mind up. With that said, if no one comes up with a solid reason why I should not go 4 link, then that's the way I'm going.
Also, in the future I want to go with a radius for some reason it would be no big deal to modify the 4 link. But substantially more difficult to change from radius to 4 link.
Not mentioning I would never know what it's like to have a front 4 link. I would always think...What if

 

[redranger4.0]

I would go 3 link over 4 link for the packaging reasons. Im having a hard enough time fitting one upper link let alone another.

Unless your name is Michael:
http://www.explorerforum.com/forums/showthread.php?t=146475&page=4

I'm running a passenger side Upper link also, or at least I will be if I ever get my rig done.

 

[FROADER]

Seems so far that the consensus is...that if you build it strong enough and safe enough that a 4 link will work fine as a DD.

Everything since the 80s that has a solid front axle is 4-link from the factory for a reason. They build anti-dive into it.

For what we drive, IMO the radius arm is the easiest and best route. But then again, I've always been a radius arm guy from desert to "crawler."

 

[IZwack]

A quarter inch wall upper link is overkill. The only reason why we run thick wall tubing on the lower links is for rock rash and high centering the link over a rock. The upper link doesn't see this type of abuse so almost all of the stresses on it is either compression or tension. So I would just run 1/8" wall for the upper(s). Read over some of the SAS thread here and maybe other forums.
Posted via Mobile Device

 

[rookieshooter]

That would be nice to use lighter on the top. The 1/4" wall is very heavy and pricy.
I'll check into what you said. Need to know these things before ordering. That also changes the weld in bung also.

I think this is how I could go about the 4 link vs radius arm thing. Once i have everything, I slid the axle under and figure on the bottom link first. Then if it looks like the upper 4 link will go in. I"ll do the 4 link. But if just too much of a PITA, I'll do the radius arm and just attach the top to axle and then to the lower arm. The top would still have the adjusting capabilities.
Now with that said, I'm I wrong in thinking even if the upper links go in fine, what's wrong with building some tabs on the lower link just in case I want to disconnect the top shorter link at frame and pivot down to bottom link tab. Like the little drawing I made. Could even pre-make some shorter top links for this also. This way I could try out both on the street and trails.
Then again maybe I'm missing something. I think it would be great to take the same highways and trails in both 4 link and radius. Then I would have all kinds feed back on pros and cons on both suspensions regarding this truck on the same trails and roads.
Now don't throw in more work. I love fabricating more then riding, so I'm chomping at the bit to get started.
Most important to me to hear all of you guys concerning this.

Here is what Fred Williams of Petersen's 4Wheel has to say regarding radius arms.

Most fabricators we spoke with admitted that building a radius-arm suspension is the easiest route but their least favorite since it will inherently bind during articulation. However, this might actually be a bonus for a street-driven truck. The binding acts like a sway bar, and that's likely why Ford, Land Rover, and 80 Series Land Cruisers all used some form of radius arms. Another option is mixing a single upper or lower link with one radius arm to alleviate the binding, but it's not our favorite layout.


I have a whole folder on suspension systems and came across this. This is similar to what I envision for the radius arm. I could just build some tabs like I mentioned earlier. Those tabs might have to be put closer to the axle if the tabs conflict with articulation in the 4 link mode. If I do the 4 link/radius arm thing it would not take a long upper link to make the triangulation. Just a short stubby piece would do.

Here's the link.
http://www.wyomingkustomz.com/product/jeep-19972006-wrangler-tj-1013.cfm