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cav fab alpha 3 link, pics of install and any issues please?

3 Links work and are proven, but I still prefer the second upper arm for extra peace of mind. As I previously said, the potential binding of the 4 link is probably negligible at the levels of flex I'm getting out of my Jeep.

If you push that front axle hard into a rock/obstacle that force is still going to transfer into the upper links. And 13,000 lbs of force definitely seems like a lot, but how many times have we seen parts break on our Jeeps that should have no problem handling the forces.

I'm not saying that 3 Links are too dangerous and that you're guaranteed to crash into a bus full of nuns and orphans. I'm just saying that I prefer the extra security of a 4 link. If I have a link failure I'm not going to keep wheeling, but I'll have a better chance of getting back to the trailer. Just like I carry spare shafts, u-joints, heims, etc that second upper control arm is a spare that's always there.
 
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in a 4000lb rig traveling 50 mph how much force does a hard breaking event incurr on the upper?

IMO 7/16" is too small for a single upper.
I run 9/16" F-911s in my upper on my 3 link, which may be overkill, but the comfort factor is worth it.
good question, im sure the calculations are strait forward... but these days i rely on my computer to do the calculations. i slept through physics mostly.

keep in mind that number i through out was for single sheer.

even still, i ran a 5/8" grade 8 myself.

and FWIW link bolts should only be loaded in tension, not in shear, ... but thats in a perfect world.
while i agree... i dont see how a bolt CAN be used in tension for a suspension.

stress_types.gif




The only way to make that statement true would be to mount the lowers on the centerline of the axletube.

you cannot do that so the upper will always share some of the load of controlling the axle fore/aft. certainly the lowers see much larger forces in this regard because they are usually mounted closer to the centerline than the upper.
i agree, i did simplify and speak in an absolute.

i dont want to say it is a moot point... but the desert guys and pedal mashers aside... the most likely time someone will see an impact like that is during an on road collision.

agreed 100%
 
3 Links work and are proven, but I still prefer the second upper arm for extra peace of mind. As I previously said, the potential binding of the 4 link is probably negligible at the levels of flex I'm getting out of my Jeep.

If you push that front axle hard into a rock/obstacle that force is still going to transfer into the upper links. And 13,000 lbs of force definitely seems like a lot, but how many times have we seen parts break on our Jeeps that should have no problem handling the forces.

I'm not saying that 3 Links are too dangerous and that you're guaranteed to crash into a bus full of nuns and orphans. I'm just saying that I prefer the extra security of a 4 link. If I have a link failure I'm not going to keep wheeling, but I'll have a better chance of getting back to the trailer. Just like I carry spare shafts, u-joints, heims, etc that second upper control arm is a spare that's always there.
fair.

only difference is you will need to run bushings to "soak up" some of the bind (radius arm as well) where a 3 link lets you run hard joints. like you said, the bind being negligible... as there are other limiting factors such as shocks or steering.

:cheers:
 
while i agree... i dont see how a bolt CAN be used in tension for a suspension.

This is a concept that is tough for many to grasp.

when a Bolt is used in a suspension link, it is basically a clamp that is clamping the joint inside the link bracket.

the clamping force is what holds the joint in place by creating a friction bond between the inside faces of the link bracket and the bushing or joint sleeve.
that is why you should always use a torque wrench and torque suspension bolts to spec.
Without the clamping force created by loading the bolt in tension (torqueing the bolt to spec) the connection would fail.

thats why every time someone suggests welding a washer over the outside of a wallowed out hole in a link bracket (especially common with the axle side TB bracket) I want to slap them. that will accomplish nothing. the INSIDE faces of the bracket are what matter. no amount of crap welded to the outside face will matter.

suspension bolts are not intended to be used as a pin, they are not intended to be loaded in shear.
if they were, they wouldn't be bolts. they would be hardened pins and they would be press-fit.


however that is the theoretical. in the practical world, they will probably see some shear force because people dont always torque them to spec, or the torque wrenches aren't properly calibrated, etc etc.
 
just for spec reference:
http://cavfab.com/ALPHA-SERIES-Jeep-XJ-3-Link_p_61.html

So, with a hard mount insert on the cast housing there will be little shock soak (hard rock or bump approach) from the upper arm/bolts/joints, Does this look like an issue for the HP D30 and 35s max?
-Dutch new Artec LCAs i have are also on the list, maybe more, ill PM you for some install ideas?

~from cav "a machined Currie Johnny joint which replaces the driver side upper axle bushing and eliminates the weak factory 10mm upper control arm bolt and moves up to a Grade 8 1/2" bolt."


Dutch mentioned having a 2nd upper arm for backup. Are there any flex/clearance issues with leaving the non diff upper mount on the axle, if I run the 3 link ( cav is made to run 4 links, but offered for 3)? ( i may not remove the other upper mount if i coulld leave it as a repair option for adding an upper arm (should the original 3 link upper break).


I have no issues with having portions of the cross-member welded, if needed, ill just need to source a local welder. other than asking cav, would welding any of this kit be recommended?)side mount brackets?

With the provided joint for the upper diff cast mount, are there any options you all would know of to upgrae the hardware for strength, or is this as Rockclimber wrote: a mechanical preference of torque to spec, rather than beefed up material to aid in the durabillity of the joint.

in fewer words, what should i be looking out for with these kits?
- thus far:
- 4 arms vs 3
- larger upper bolts
- welding parts vs direct bolt on ( im not a fan of reading "bolt on", but I also dont know the true strength difference that either install method provides.
what things, based on their build, do I not have to look out for?

this has been a lot of great information thus far, Thank You all for posting all of the above!
 
in fewer words, what should i be looking out for with these kits?
- thus far:
- 4 arms vs 3
Personal preference really. I like having 2 upper arms, but either way you'll be fine.
- larger upper bolts
That 1/2" bolt is a fair upgrade.
- welding parts vs direct bolt on ( im not a fan of reading "bolt on", but I also dont know the true strength difference that either install method provides.
what things, based on their build, do I not have to look out for?
The CAVFab setup has plenty of tie-ins to make it hold up as just a bolt in. I wouldn't be worried about that at all

this has been a lot of great information thus far, Thank You all for posting all of the above!
 
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Stupid question - is there any particular reason why the single-link side of this sort of system couldn't be a y-link like in a radius arm setup? Then at least the upper link that goes to the frame is only shouldering part of the rotational load even if it doesn't provide that 4th axle-frame connection like some above have expressed preference for.

Would something like this be called a "hybrid" setup, or a "3 and a half link"?
 
Only way I would bolt on is with some sort of frame stiffening otherwise what exactly are you bolting to?

Honestly, I would beef up the frame with 3/16 plate before mounting any system where the front axle is positioned by the crossmember. That crossmember better be mounted to something more than the tin of the unibody.
 
I think there would be some serious binding with that. One side would try to rotate (or not) the axle while the other in a totally different arc.

And this is why I posed the question - I don't know enough about suspension designs to know that.

Thank you for the feedback.
 
There are people who run a Y-Link or radius arm on 1 side and just a single lower link on the other. I scoped out a 4500 car setup that way too. Its believed to be less "binding" than a full radius arm/Y-link setup. I personally think all this binding talk is exaggerated. I've seen and experienced the capabilities of radius arm setups to flex, and never had an axle tube ripped apart or mounts deformed/damaged. That's even with all solid mounts at both the frame and axle. I'm not saying its not there, just that's its a lot less of an issue as some would like to believe.
 
Agreed. What I got from his question was what would happen with a 3 link with the addition of a radius arm on the side opposite the upper link.

Had a friend who had a tj with one radius arm set up like you said Dutch. Seemed to work fine, never had issues with it.
 
Agreed. What I got from his question was what would happen with a 3 link with the addition of a radius arm on the side opposite the upper link.

Yep, that was exactly what I was wondering.
 
So a 4-Link, Radius Arm setup? Seems odd. Most likely it’d explode and cause you to drive into a school bus full of nuns and orphans.
 
Stupid question - is there any particular reason why the single-link side of this sort of system couldn't be a y-link like in a radius arm setup? Then at least the upper link that goes to the frame is only shouldering part of the rotational load even if it doesn't provide that 4th axle-frame connection like some above have expressed preference for.

Would something like this be called a "hybrid" setup, or a "3 and a half link"?

Similar to ironrocks iron-y long arm suspension?

https://www.ironrockoffroad.com/product/xj-critical-path-long-arm-upgrade.html
 
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