nukegoat
Should have bought a Jeep
I tossed a set in the trash the other day that I would have volunteered too.
Flexing the 3 link (15 Viewers)
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I tossed a set in the trash the other day that I would have volunteered too.
maxamillion2345
Franken-80
At least I used safety washers!Dude you are going to die with all that steering in single sheer!
I'm joking of course.
Does anyone know the relationship to the preferred caster @ ride height and the axle end bushing holes? Ie: if caster is at 3 degrees are the bolt holes on the arms at zero(90 degrees) on a stock height 80.
I could lay it out and find it if i had some spares, but i think slee published this some where in his caster plate discussion?
Caster plates seem to find a little window where caster is 'okay' and the factory driveshaft is usually, 'okay'. Both of these angles actually suck, but its a comprimise.
I can bend arms with no heat, just need a definitive measurement to derive the amount to bend. The caster would be cool, but anything after ~4.5" of lift pushes pinion angle into part time kit.
I could lay it out and find it if i had some spares, but i think slee published this some where in his caster plate discussion?
Caster plates seem to find a little window where caster is 'okay' and the factory driveshaft is usually, 'okay'. Both of these angles actually suck, but its a comprimise.
I can bend arms with no heat, just need a definitive measurement to derive the amount to bend. The caster would be cool, but anything after ~4.5" of lift pushes pinion angle into part time kit.
Using a radius arm mounted like the factory still upsets roll center specific to the front suspension badly when lifted. The roll center travels from panhard centerline height up to the chassis at radius arm angle.
If you want it to be worth the effort you need two lower control arms that are flat and/or triangulated to remove the upward angle(oversteer) upsetting
the roll center.
Sure, raising the panhards is the best bang for the buck/effort. But if youre chasing the ultimate be done with it and wheel forever. You need to mess with both issues.
If you want it to be worth the effort you need two lower control arms that are flat and/or triangulated to remove the upward angle(oversteer) upsetting
the roll center.
Sure, raising the panhards is the best bang for the buck/effort. But if youre chasing the ultimate be done with it and wheel forever. You need to mess with both issues.
I cant post pics worth a s*** on a phone or id draw this stuff out on graph paper...
Goto '4wheelunderground.com' and in the table of contents is 'suspension encyclopedia'. I think its a great overview in laymans terms and touches on roll axis--> roll center, radius arm, 3 link, etc, etc. Even antisquat and dive, but thats a can of worms thats more of an issue in the rear on these trucks as the increased antidive we create in front does little/no bad, but nicely promotes front axle traction and prevents brake dive.
Goto '4wheelunderground.com' and in the table of contents is 'suspension encyclopedia'. I think its a great overview in laymans terms and touches on roll axis--> roll center, radius arm, 3 link, etc, etc. Even antisquat and dive, but thats a can of worms thats more of an issue in the rear on these trucks as the increased antidive we create in front does little/no bad, but nicely promotes front axle traction and prevents brake dive.
Not mounted like factory.....don't know that it matters.
I'll be the first to admit being bolt on ignorant.
What I was proposing was eliminating the "bracket" and welding the mount to the back side of the axle, where the DS arm attaches.
Sorry, i dont know you guys yet
Pics this time, man. PICS.
The gummy cougars love posing for them.
nukegoat
Should have bought a Jeep
The superflex radius arms are still radius arms. You can move the bushings closer together but you're still trying to twist the axle tube. The extent to which you're turning that housing into a giant torsion bar is easy to approximate - measure the difference in angles between the arms and the frame mounts.
You could also make the radius arms less bindy by using longer radius arms (so less angular displacement is required) or softer bushings (bad idea, IMO) OR by moving the radius arms to the top of the housing (if lifted) so that the angular displacement required for every inch of linear displacement is less drastic since the arms are closer to being flat again. Some people are stronger advocates for this approach than myself but it does have a few positive side effects related to ground clearance.
You could also make the radius arms less bindy by using longer radius arms (so less angular displacement is required) or softer bushings (bad idea, IMO) OR by moving the radius arms to the top of the housing (if lifted) so that the angular displacement required for every inch of linear displacement is less drastic since the arms are closer to being flat again. Some people are stronger advocates for this approach than myself but it does have a few positive side effects related to ground clearance.
nukegoat
Should have bought a Jeep
The 4wheelunderground encyclopedia is good but does make some oversimplifications I don't agree with, namely the idea that a non-parallel 4-link is a glorified radius arm setup. Yes, parallel links would avoid the links trying to twist the axle through 5 feet of travel, but correctly designed link geometries (model the rear of your 80 if you don't believe me) have very little pinion change through their usable travel. Radius arms, by definition, are just swinging the axle around the radius drawn from the lower control arm frame mounts.
nukegoat
Should have bought a Jeep
For those looking for more academic information on suspension design, Carroll Smith's Tune to Win is a good starting point. Yes, most of the chassis engineering literature is about racing, but kinematics are kinematics.
Cliffs notes: Engineering often requires you to make compromises
Cliffs notes: Engineering often requires you to make compromises
maxamillion2345
Franken-80
Could always do a custom wristed radius arm, not very difficult...
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I am no expert. But I would suggest burning things on permanently with a bigger machine. I have a Miller 140 and it is rated up to 3/8". But honestly a bigger machine is needed in my shed. It works for now but when I get to welding on suspension bracketry and more (soon) a bigger machine is going to be used. You can certainly heat steel up with a torch and get good penetration with a 110v but I just don't suggest that on a forum or for stuff you need to really stay put. Somebody in your circle of friends must know somebody with a 220v machine who can come burn it all on with nice welds for a 24 pack of beers and $100. If you are not using gas on your 110v, get on it! If you don't have the power for a 220v machine, rent a generator for the day.
I got a set too, we might have to give it a go before I throw down $1k for HF knuckles. Going to sort out exhaust first since I got a bad cat.
Cheers
fzjconvert
one hand, two ducks
Ding, ding, ding you hit it right on the nose. I think the superflex arms moved to the top of the housing is the ticket. You would have the best of both worlds. You would have the tried and true stability of the radius arm and I would venture to say 90%+ the stretch of and I have to preface this by saying I had been
cogitating over this very issue for longer than I care to admit. None the less, 90%+ the stretch of a premium 4 link like that of 4WU's I know that is hard to believe but the superflex arms work incredibly well. However, 4WU quality and workmanship is second to none that I have seen in the 34 years since my first motor job. How I know, that would take to long and the war department just kissed me on the neck and said "I just shaved my legs" so I'm out peace.
cogitating over this very issue for longer than I care to admit. None the less, 90%+ the stretch of a premium 4 link like that of 4WU's I know that is hard to believe but the superflex arms work incredibly well. However, 4WU quality and workmanship is second to none that I have seen in the 34 years since my first motor job. How I know, that would take to long and the war department just kissed me on the neck and said "I just shaved my legs" so I'm out peace.
fzjconvert
one hand, two ducks
Not sure what happened with my post but will edit tomorrow
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Honestly, no idea. I do know Krazytoy's 80 he set up with about 4.5* castor (correct me if I am wrong bro) with the c&t. He had something like 2.5" lift. He was limited buy the tie rod behind the axle, obviously. I drove it right after he did that and a bunch of other work. If friggin rocked super hard and drove like a brand new truck. Two finger driving on crappy rutted country roads no probs. Tracked like a dream. That's what I am after. I know leaf springs is not the same at all but he and I set up my 60 with 5* on a c&t and it was the best driving leaf spring truck I have ever owned. I got more lift then he did so have worse castor. Correct me if I am wrong but don't you want 1-2* more than stock on the castor if stepping it up in tire size? So 35-37's 4-5* should be just right? We got set up to do mine and c&t it a few months back, found I had 5* the wrong way with stock bushings. Meaning to get to 4-5* I needed 9-10*! We were only going to be able to gain 3-4* c&t'ing with the stock configuration. Not worth it. HF knuckles will allow much more on the c&t, other option we came up with was bending the radius arms. Other than this it is all the other junk everybody uses, bushings, plates, drop brackets, new radius arms, ect ect ect. I got a 5.7L v8, 4L60e and split case and almost no way I think I can fit a DC shaft. So I not only need to dial in my castor I need to dial in my pinion angle. It can be done!!
All the geometry does make sense and needs to be applied but when sticking with the radius arms less comes into play in my opinion. All you really need to do is replicate the stock geometry in a 4" (or 2" or 3" or 6") configuration, no? Only reason I don't go 3-link and c/o's is I plan to take this truck outside the USA so want it to be lifted 4" with stock components and drive excellent down the road. To do that all I think I need to do is dial in castor, pinion angle and get the panhards as flat as possible. Retaining stock bushing and components is a go for me with this kind of use in mind.
On the topic of a 3-link, much easier to do and solve the issues imho. Especially if going c/o's. Less room of course with the coil springs. If I was not considering trips south of the border (long pavement drives) and or re-sale I would go 3-link in a minute.
Cheers
While ill admit to adjusting the front slightly to get what i prefer, with emphasis on slightly, im ALL ears on this statement. Hope youre ready to back it up friend.
Won't work and no more beneficial than they current orientation.
First, the PS arm would hit the frame rail.
It's my feeler for wheeling Braille, to give an idea the arch, which I grown accustomed to and would have to concoct some other method of device to bang on, letting my know chit's getting real, in it's absence.
Second, the attachment on the DS is the critical component of the SEs ability to articulate and since it's attachment is a vertical orientation on the back of the housing, flipping does nothing, plus the arms are substantially longer already, so, in theory, they return the axle to the correct location and orientation.
They've already "fixed" one aspect, and, if what everyone else is saying is true, all it needs is the panhard/draglink raised to correct the undesirable attributes....of course, that's after a double, double cardan driveshaft and cut and turn, since those critical instances weren't achieved in the original arm design.
Someone smarter than I wants to run through a calculator to prove me dead ass wrong, I'll gladly measure.
Sounds like a nice girl.
The obligatory "pics or I'm calling BS" reply suits, but please wax that ass, first.
I did get smaller on screen....
This is irrefutable truth and discussions of their merits probably don't belong in a 3 link thread, if comparing, solely, geometry and movement.
That said, I've a selfish, ulterior motive in attempting to compare, primarily a planning method to fix my chit once and for all, because I'm tired of it and it's bogged down completion of the easiest "build" I've undertaken.
Not bragging, trust me, but I'd pit the SE arms and flexy coils against what three linked 80 on coils, I've seen, any day, IF articulation and coil retention are the determining winning factors.
The arms are a fail from a caster correction and pinion angle perspective, but any linked will require C&T, since inherent to the OE housing is the inability to have you cake and eat it too, IF AWD and a constant barrage of soccer moms beating a direct path for a Sybian style ride pose a problem in your marriage.
Honestly, no idea. I do know Krazytoy's 80 he set up with about 4.5* castor (correct me if I am wrong bro) with the c&t. He had something like 2.5" lift. He was limited buy the tie rod behind the axle, obviously. I drove it right after he did that and a bunch of other work. If friggin rocked super hard and drove like a brand new truck. Two finger driving on crappy rutted country roads no probs. Tracked like a dream. That's what I am after. I know leaf springs is not the same at all but he and I set up my 60 with 5* on a c&t and it was the best driving leaf spring truck I have ever owned. I got more lift then he did so have worse castor. Correct me if I am wrong but don't you want 1-2* more than stock on the castor if stepping it up in tire size? So 35-37's 4-5* should be just right? We got set up to do mine and c&t it a few months back, found I had 5* the wrong way with stock bushings. Meaning to get to 4-5* I needed 9-10*! We were only going to be able to gain 3-4* c&t'ing with the stock configuration. Not worth it. HF knuckles will allow much more on the c&t, other option we came up with was bending the radius arms. Other than this it is all the other junk everybody uses, bushings, plates, drop brackets, new radius arms, ect ect ect. I got a 5.7L v8, 4L60e and split case and almost no way I think I can fit a DC shaft. So I not only need to dial in my castor I need to dial in my pinion angle. It can be done!!
All the geometry does make sense and needs to be applied but when sticking with the radius arms less comes into play in my opinion. All you really need to do is replicate the stock geometry in a 4" (or 2" or 3" or 6") configuration, no? Only reason I don't go 3-link and c/o's is I plan to take this truck outside the USA so want it to be lifted 4" with stock components and drive excellent down the road. To do that all I think I need to do is dial in castor, pinion angle and get the panhards as flat as possible. Retaining stock bushing and components is a go for me with this kind of use in mind.
On the topic of a 3-link, much easier to do and solve the issues imho. Especially if going c/o's. Less room of course with the coil springs. If I was not considering trips south of the border (long pavement drives) and or re-sale I would go 3-link in a minute.
Cheers
Thanks man, Yes, it had about 4.5* with about .2* of cross castor. I believe if we built you a 3 link using Johnny Joints you would be very happy with how it drives, carry a few inexpensive rebuild kits and the tool to do them and hit the road. I know we have talked about this many times over many a beers... I say ditch the stock arms and lets have some fun!
