Originally Posted by RockRunner85
You got me there. Is that a custom front axle with custom short arms?? Looks like it'd give you a better ride. Want to fill me in?
Those are the Currie J-Arms, installed on a HP D30 axle. I also have the J-Arms installed on the rear axle.
All the advantages of a "long arm" kit, and none of the disadvantages.
This is considered a "medium arm"....
A *big* problem with the typical LA kit, if you play (wheel) in the big rocks, where clearance is a premimum, is the lose of clearance from those 'ole long arms hanging way down there.
They get hung up all the time, and have been bent on a somewhat regular basis.
What needs to be done, with the control arms, when you lift a Jeep, is to try and get the angle back, as close as possible, to parallel to the ground, when the Jeep is sitting level.
If you go look at a lifted Jeep with stock length arms, you'll see that the logically way to do this would be to raise the end of the arm that's been moved downward. Right ? That would be the axle end. When you lift a Jeep you move the frame up higher from the axle, thus "lowering" the axle end of the control arm, or, looking at it the other way, raising the frame end of the arm.
The logical thing to do is to bring the axle end of the arm back up, towards the frame end.
The LA kits don't do that, as it involves welding and some moderate fabrication ability. So, what they do is raise the frame end of the arm (which is already above the axle end) higher, and then, to try and moderate the angle, they make the control arm long, moving it back to the edge of the xfer case.
Look at the photo (above) of the LA kit that Bigwalon posted, and it'll become obvious what I'm talking about.
Another goal, is to try and have the axle, when it articulates, move more straight up and done, instead of in an arc.
Again, the LA kits do that by lengthing the arms.
The J-Arms do it by the way that they wrap under the axle, mounting on the other end.
Regarding the effective angle of the arm, it doesn't matter how the arm bends nor how deep the bend is. The effective angle is a straigth line drawn between the center of the two mounting points.
Put a straight edge (edge of a piece of paper or something), up to the screen, in the photo that I posted above, and set it such that the straight edge goes from the center of the mounting bolt on the axle, to the center of the mounting bolt on the frame. Notice how little angle is in the arm now.