relocation the lower control arm mounts on the axle to the top of the axle?

[ktm racer 419]

almost every non stock axle i have seen under a jeep has had the lower mounts flush with the axle tube.

nothing will spontaneously combust if you move them up a couple inches

 

[ROBZ95Xj]

nothing will spontaneously combust if you move them up a couple inches

if you didnt use the link calculator it will

 

[vetteboy]

The first problem would be messing with your instant center by bringing it above center and in turn would completely screw your antisquat numbers.

The more important issue is strength. Never mount your lowers above center of the axle. It will act as a giant lever and the torque from your tires to the ground will be greatly multiplied and add substantial stress to your new mounts and control arms. Even if you could build strong enough mounts dont even think about using your stock control arms.

Bringing the instant center above center...

Above the center of what?

And what do you mean by 'screw'?

Way I see it, raising the axle end of steeply-angled control arms would lower the instant center, which decreases the anti-squat (or anti-dive as it may be). Typically not a bad thing.

Wheel recession & roll axis would also improve.

Just keep the center of your control arm joint at center or just below the center of the axle tube.

It's not a strength issue if you build it strong enough, and the centerline of the axle tube isn't some magical line that suddenly sends forces to infinity and beyond.

I think you're way overstating the effects here. Curious to see some numbers or photos, if you have 'em handy.

edit: I'm not saying I'd advise doing this with stock control arms or bushings. But with some pretty standard hardware you can get along just fine...

 

[srimes]

It's not a strength issue if you build it strong enough, and the centerline of the axle tube isn't some magical line that suddenly sends forces to infinity and beyond.

x2. Plenty of examples of axles controlled from mounts on the top side. Just look at leaf springs.

Look at the forces that the control arms are dealing with: where are they comming from? Yes, they're transfered through the axle housing, but that isn't where they start. The forces start at the tire contact point. So the torque depends on the distance from the tire to the control arm mounting points, not the center of the axle to the mounting points.

This is one reason big tires add stress, and spring under has less axle wrap than spring over.

 

[kastein]

Doesn't make sense to me, but I might not be thinking about it right.

That being said I had a pretty goofy amount of axle wrap with SUA and 2" lowering blocks in my MJ... it has mostly gone away now that I dumped the blocks and kept it SUA.

 

[srimes]

I haven't played with 4-link calculators much at all, but I downloaded this one posted on pirate:
http://www.pirate4x4.com/forum/showthread.php?t=204893

I played with it a little and looked at link stress vs. mounting height and it confirms what I was thinking: stress goes up based on height vs. the ground, not vs. the axle. :lecture:

Of course for a given axle position (tire size) raising the mounts increases the link stress. But that's because the links are higher from the ground.

So say you plan on running 33s and are considering raising the axle mounts (upper and lower) 4" instead of drop brackets. The links would see stresses similar to running drop brackets and a tire with 4" more radius: 41s. Intuitively a lot more stress, but not obscene or undo-able.

But I'm just web wheeling here. No personal experience to back up these theories. :dunce:

 

[Builderxyz]

relocation the lower control arm mounts on the axle to the top of the axle?

I have been searching and can not find anything about doing this...

it seems like a great idea and it would be way better than drop brackets

What is it that your trying to accomplish?is it LCA bracket clearance or what?

 

[kastein]

he got banned months ago for a variety of things... I don't think he'll be back to answer that

 

[Goatman]

Wow! Older thread but so much bullsh1t and misinformation on the first page. People should only comment on the internet when they actually know something about the subject.

 

[Royal_Highness]

The one great thing about the internet... Incorrect information. I know very little about the subject applied in the real world. But the general concept that I know, I knew they were just talking to talk. Got to love the internet.

 

[srimes]

My bad on reviving this thing. I looked at the date and thought it was only a couple months old :gee:. Still haven't gotten used to it being 2012.