I know there are guys that have done this mod and I like the idea, but does anyone have a write-up with pictures on this operation?
Front control arm flip
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Are you talking about where you cut off the brackets, and weld them on top of the axle?
I've heard of folks doing that mod down in Aussie land, not sure anyone here has done it.....
I've heard of folks doing that mod down in Aussie land, not sure anyone here has done it.....
i have done this mod, its PITA but the pro's of it are worth it in the end..
i havent really got any decent pics of it, ill go take some if anyone needs em.but ill post what i got for now
i havent really got any decent pics of it, ill go take some if anyone needs em.but ill post what i got for now
Please do. This mod has interested me for quite some time, but I haven't found much detail on it.
How did you determine where and at what angle to weld on the brackets? Were you able to reuse the brackets, or did you have to fab new ones? At what height of lift does this become a feasible option? Any resources you used online?
I have considered this for some time, just never really had the time or money to mess with it.
From what i've read, you need about 6" of lift to pull it off.
As for orienting the brackets.... use a dial indicator before cutting the original brackets off to measure your current caster angle. Cut the brackets off, set the axle back to the angle using the dial indicator, then weld the brackets back on top.
but the more i thought about this the more i wondered what am i really achieving? So the arms are not underneath which gains some ground clearance, but not that big of a deal as there are other things hanging down. You still have all four bushings in place, so i dont see flex improved any. So i'm not sure what the gain really is?
From what i've read, you need about 6" of lift to pull it off.
As for orienting the brackets.... use a dial indicator before cutting the original brackets off to measure your current caster angle. Cut the brackets off, set the axle back to the angle using the dial indicator, then weld the brackets back on top.
but the more i thought about this the more i wondered what am i really achieving? So the arms are not underneath which gains some ground clearance, but not that big of a deal as there are other things hanging down. You still have all four bushings in place, so i dont see flex improved any. So i'm not sure what the gain really is?
nuh mate just did it all in my head lol, im running 4" coils, 2" BL, you can do the castor at the same time too..yes i reused the brackets, probably easier to just make new ones up , i pissed aroudn for ages notching them out to fit the diff,you just make sure your castor is right and then notch the bracket to suit ,i did this with full weight of the truck on the diffs so it was hard to hold castor in place and weld the brackets at the same time ..
their is an article on outerlimits4x4 that explains this all,including a another pic of how mine is done.
i think you might need to sign up to read it though.
Outer Limits 4x4 Board :: View topic - Flipped Radius arms
I guess it'd be a way of correcting caster without going to bushings or plates. Agreed that clearance isn't a major factor there.
I do know that with most of the bigger caster correction methods, you start to run into interferance, binding, or rubbing (IE: drive shaft on the sway bar). Would this avoid those issues, or introduce new ones?
Probably the biggest benefit after lifting an 80 is the ability to keep the front control arms as parallel to the ground as possible. Control arms, especially on the front, like to run as flat as possible. This keeps them responding to bumps/impacts much more natural.
When you put them at a sharp angle, now the bump/impact is traveling at an angle, whereas if they are flat the axle is more likely to want to travel up or down like it was designed to do.
Also, when you see a lifted front linked suspension with sharply angled arms attempt to climb ledges, the front wants to "walk" under the truck instead of climb the ledge/rock.
Jack
When you put them at a sharp angle, now the bump/impact is traveling at an angle, whereas if they are flat the axle is more likely to want to travel up or down like it was designed to do.
Also, when you see a lifted front linked suspension with sharply angled arms attempt to climb ledges, the front wants to "walk" under the truck instead of climb the ledge/rock.
Jack
I haven't and still don't buy this. I can see the relationship of the frame mount and axle's center coming into play like this. But just moving some brackets around that doesn't change that, no way.
Damn Rick, you're making me rethink this, and I think you're right. Changing the way the axle is connected to the frame wouldn't change the direction of force. You'd have to make the control arm longer to affect anything, which brings up its own set of issues. However, I don't think the axle's center is the starting point of force, but rather the point on the tire which contacts the road surface (be that a smooth road or a ledge). If true, that makes tire size the big factor- which we already knew, but there's a slightly different dimension at work here.
For our purposes it's not so much the road that's the issue, but the rock you're trying to get over.
A simple example was taking a loaded wheel barrel, and pushing it. Especially if you're trying to get over a bump/rock/etc, the flatter the arms the easier the tires will go over that bump. If you tip the arms up at a 30% angle, then the wheel will want to push back more than up.
In the wheel barrel case, we can simply lower our arms, which is the same as doing a drop bracket on the frame side of the arm.
The other option is to relocate the other end of the handles, and move them up. Some wheelbarrows are designed this way for exactly that reason.
Compare:
Having used both of those types, I can tell you which I'd rather use. ;p
It's quite amazing at what a difference an inch or two makes, and what just a couple degrees of angle can do to moving a heavy load. In our case, we're actually relocating the arms quite significantly, while the actual mounts stay fairly close in place, the arm itself is being fipped upside down, meaning the arm is moving a lot. Even the mounts themselves moves about an inch or two.
There's a pic with the estimated mounting line. Consider the difference between that, then add the arm itself into the equation. You're moving things around in there quite a bit.
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By putting the arm above the axle, you're not changing the direction of force, only the way it is transmitted between points, which is irrelevant. Moving the frame side mount toward the rear would flatten the arms and change the direction of force. Changing where the arms are connected to the axle won't change the direction of the force- it still has to go from the axle to the frame mount. You could curve the arm up into the engine compartment and not change the direction of force- the wheel will still want to move rearwards if it meets resistance, and the shock load will still travel the same line, with the same result in ride comfort.
What I get from Rick's explanation is that the line that needs to be parallel to the ground is not the arm itself, but rather the line between the frame mount and the axle. That makes perfect sense to me.
That's my theory anyway, and I'm sticking to it until convinced otherwise. Tools R Us, my personal suspension guru, has explained the benefit of putting the arms above the axle and I bought into it, but upon further thought I believe Rick has a valid point. Maybe he can jump in here and explain it to me again.
What I get from Rick's explanation is that the line that needs to be parallel to the ground is not the arm itself, but rather the line between the frame mount and the axle. That makes perfect sense to me.
That's my theory anyway, and I'm sticking to it until convinced otherwise. Tools R Us, my personal suspension guru, has explained the benefit of putting the arms above the axle and I bought into it, but upon further thought I believe Rick has a valid point. Maybe he can jump in here and explain it to me again.
The wheel barrel example is about leveraging the load, I don't see how that applies. But knock yourselves out. Seems like a hole lot of work so I hope it worth it.
It's not the act of flipping the arms that changes the geometry, but rather, raising the axle side mounting brackets that makes the arm geometry 'flatten out'.
Raising the brackets on the axle end performs a similar function to relocating the frame side mount towards the rear of the vehicle.
Have you talked to any of the owners of this mod? Even after you hammer out all the angles and bracket mods - you still have a problem when 1 of the front wheels goes to full stuff. If you take a look under your front end, you'll see that when you reverse the control arm to the top of the axle, it now sits between the frame and the axle. Just off the top you're loosing 3" of upward travel. And if you bottom out the suspension hard, what kind of damage will you do to bushings and brackets? Not to mention now exposing your previously protected tie rod to rocks and such. How 'bout relocating the axle ends of the anti roll bar and any new clearance issues with control arms?
I think I agree with Landtank and it would be worth it to talk to some one who's already done it and their take on pluses and minuses of the mod.
Okay, maybe I don't fully understand it, but here's my shot at it.
Here's my quick and dirty photoshop, with not-to-scale images.
Stock Truck:
So with a "worst case scenario" type situation, the main force would be roughly in the middle of the tire, or at the same level as the axle. This would be if you were trying to climb a rock, or a ledge, or out of a hole.
With a stock truck, the arms are (relatively) flat, meaning that the force comes straight back. For this purpose, the axle can only move up or down. Since the arm is below the axle it will have a tendancy to move down rather than up, but the weight of the truck on the ground should counter act that.
Lifted Truck, stock arms:
With a lifted truck we are not only lifting the frame side mount up, but also rotating the mounting brackets to point more towards the rear. Exactly like when you lift a wheel barrels handles up, the wheel is gong to want to push down and back rather than straight back or back and up.
Lifted Truck, flipped arms:
By flipping the arms you're going back to the more 'neutral' position where the force will go more back than down.
If you think about it, the wheel is going to leverage the axle, the axle will leverage the arm, the arm will leverage the frame. The axle is centered on the wheel, so the leverage is pretty much directly from the obstacle to the axle in a straight line. The axle will then take that force and apply it on the arm, but the arm isn't mounted in the center of the axle so it's not a straight shot as the force against the wheel is.
With the arm mounted below the axle, the bias is going to be to lever down on it. With it mounted above the axle, the bias will be to lever up on it. This can be tested out pretty easily, tape a pencil (or some other lever) to an object and apply force against the object as in the diagram above. See which way it wants to move. Now flip the pencil over, and do it again. It's always going to want to move back, but it's that upwards/downwards bias that we're interested in.
I hope that makes sense. As I said before, I'm thinking this through myself so there very well may have been something else I've missed.
As I understand it, it's not really worth doing unless you're a minimum of 4" of lift, due to the issues you just outlined. Most people who seem to be doing it are in the 6" range, and many are running 35" tires or bigger. Typically in those cases they don't have much upward travel anyway, because the tire will interfere with the wheel well before the arm interferes with the frame.
It's similar to saying it's not worth it to upgrade to 35's from 31's, because you lose 2" of upward travel.
Again, just my understanding of it.....
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Tapage
Club 4X4 Panamá
I'v seen this mod ususally in pretty lifted trail rigs in Australia .. all 'em running 35 plus tires .. but always that I seen it was in Nissan Patrol .. coz the control arm on it's setup where the control arm it's conected to the frame are not throught the same method that you see in a Cruiser ..
here is ..
but here are a 7" drop arm for Patrol ..
here is ..
but here are a 7" drop arm for Patrol ..
Well after having a hand in and watching the result of several linked front suspension on rockcrawling rigs, believe what you want, but the geometry is there. As mentioned later in this thread, the force doesn't change, just the angle of that force.
The wheelbarrow is not just about "leveraging" the load. Go out back and load up the wheelbarrow, now hold the handles up near your chest and try and take the wheel over an obstacle, doesn't have to be that big, after you dump that load and feel the handles in your armpits, load it up again, lower the handles back down below your waist, hit the obstacle again and see whether the wheel rolls over it this time or not. I await the results.
Simple example in the way/angle that force is transmitted, simple geometry.
Now having said all of that, I have no intention of "flipping" the arms on my 80.
Jack
well the stumbling block for me is this,
If in the stock location the arms cause the axle to move forward .5" when raised 4" and it's the same after the flip. Then how is the resistance changed?
I understand that when lowering the rear it changes as the forward movement has been decreased to near zero or even negative.
Lowering the rear makes sense to me but the arm flip doesn't unless you are altering other things as well.
If in the stock location the arms cause the axle to move forward .5" when raised 4" and it's the same after the flip. Then how is the resistance changed?
I understand that when lowering the rear it changes as the forward movement has been decreased to near zero or even negative.
Lowering the rear makes sense to me but the arm flip doesn't unless you are altering other things as well.
