I've got the PMF ones. Work great. Quality stuff. Biggest thing with them is getting them torqued to their proper specs.

 

Yea I heard that too. That’s probably what I’m gonna go with when I switch out to the 4.5” springs. Just curious about the Carli. Really haven’t seen anyone run them on the 2017’s. I know Clay at Voodoo diesel has them on his ‘15.

 

Mine popped after a month of operation. Did a retorque at 500 miles like recommended by Trevor. Started getting a little upset until I decided to check it out with a different torque wrench. One I used for the install and retorque definitely needed to be recalibrated.

 

Yea I’ve heard that about their radius arms and their adjustable trac bar. I went with Carli adjustable trac bar.

 

Just working off of some theoreticals here, I would guess you probably "need" RA drop brackets before you "need" replacement RAs. It might be splitting hairs and might not make a bit of difference outside of academia and once placed in application, but here is the "why," as I understand it:

1) The steeper the RA, the more anti dive is introduced into the system, and the less weight shift towards your front axle under braking, where about 70% of your stopping power comes from. Assuming that you are not lifting the rear an equal amount, the greater the anti dive, and it is exacerbate when loaded/towing.
2) The steeper the RA, the more the front axle swings and accelerates forward under compression. With the RA being fixed at the frame, as it moves towards parallel during a bump event, it has to push/accelerate the axle forward. This, theoretically, impacts ride, making it rougher. In speaking with Carli, they suggest that a 4.5" system rides better than a similarly equipped 2.5" system.

RA's definitely look much cooler than drop brackets, but there is a reason that 4.5" Carli kits come with drop brackets: it corrects geometry, thus optimizing ride and handling.

When (and if) I talk myself in to going up, from a RA standpoint, I would likely select the PMF adjustable arms. Carli, for sure, wins on vanity. PMF wins on functionality. The main advantage for the PMF in my estimation, is the ability "lengthen" the arm at the rear joint. If you have having clearance issues with the rear side of the front fender, it could allow you to nudge the axle forward for increased fender clearance.

 

You're partially correct.
PMF arms name is slightly misleading, they are still function a radius arm not a 3 link, or even a wristed radius arm setup (where one link has only one connection to the axle or a move-able joint to remove bind)
They function just as the factory arms but add strength, larger serviceable joints and introduce adjust-ability to add caster or lengthen the arm for proper/desired fore and aft axle placement. possibly additional tire clearance (I haven't seen any in person to measure)

Carli arms, function just as the factory arms with the addition of strength, additional tire clearance, an additional 1.25* of caster built in, and large serviceable joints.

While you can run PMF arms with higher lifts without the use of a drop bracket, they really do nothing to improve ride that comes with running the arm at a steeper angle. the more you lift a radius arm suspension and the steeper the angle the more of that force is transferred back into the chassis and hammers on the rear arm joint. The drop bracket helps maintain a flatter angle on the arm keeping it in the center of its arc at ride height transfering energy into the shocks and springs the way the suspension is intended to absorb forces of movement.

Given all other things the same the ride difference between the two arms will be negligible, Its going to boil down to looks and features.
If one intends to try and push up caster numbers beyond what you can achieve with offset caster bushings and the additional 1.25* of the carli arms then PMF has the advantage. If you run an aftermarket bumper and want to move the axle further forward a bit for clearance at lower rear of the fender another nod to the PMF

 

Never referred to the PMF or Carli parts as anything other the radius arms. Sounds like we are in alignment....likely the only thing separating us is semantics.
Good point on the front bumper....rather than springing for an aftermarket unit, one could save a couple thousand and install a front bumper spacer kit and a 2wd valance.
To the main point I was trying to make, on the list of "needs," my opinion is that returning the RAs to as flat as possible ranks higher than installing after market arms....especially once you move beyond a level to a 4.5" lift. I was just cruising PMFs website and came across RA drop brackets in stock, 2.5," 3.5," and 4.5" drop variations for 2005-16 trucks. They may or may not be the same units for 2017s. Another way to flatten the angle is go 4 (er 5) link. The upper link mounts in the stock RA location and the lower link is dropped in a new bracket. Of course, that could introduce some other issues, haha.

 

I would purchase the Carli 4.5" coils and PMF radius arms first and install. If you don't like the angle of the RA then add a drop bracket and have it realigned. Just my .02

I plan on doing the same but I can seem to decide on the springs...

 

What about these...no need for a drop bracket up to 4.5" of lift. Lewis Built Performance

Home

 

Looks like Carli doesn't make RA for the 17+ just drop brackets for the 17's with 4.5" lift. So PMF or those Lewis RA are a good option.

 

look again. they sure do make radius arms for the '17-up

 

Some would opine that the "need" to correct the angle of the RA in order to optimize and return suspension kinematics to the stock design happens well before 4.5" of lift. In dissecting the language that Lewis Built used in their add, they are simply saying that an appropriate/OEM caster angle can be achieved with lifts up to 4.5" because their upper link is adjustable. Without dropping RA mount, the angle of the RA is steepened, brake anti-dive is increased, and suspension compliance is decreased. How much will it really affect performance? Are we splitting hairs? Carli seems to think that dropping the mounts is more important than replacing the RAs, as they are an option in 4.5" kits.

I kind of look at it like this: Ford probably was very specific in designing the stock front suspension. The further we deviate from those angles can only serve to compromise ride, handling, and braking.

 

Yea my dealer told me wrong.

 

IMO: if you are running Carli, stay with Carli. I believe they do way more R&D and put more engineering into their products.
I have the 2.5 and have been thinking about the 4.5. I would do the whole shebang. I wouldn't mix and match radius arms.