optimum location of Ford radius arms?

For my HP44 swap...

Planning on using the Ford radius arms, sleeved and with a superflex joint at the crossmember end...

Having a custom HD crossmember made that is very similar in attachment to unibody like Kid4Lyf's...

I've seen the arms mounted right next to the frame rails and a few towards the center...

They're going to tuck up as much as possible... (that's the plan anyway)

Anyone run into clearance issues depending on placement?

Is it ok for the arms to follow the stock Ford angles?

Am I correct in thinking it would be better to keep the arms straight and let that determine the position of the brackets or let the brackets determine any possible bends on the arms?

There's so many variants...

What's worked well for everyone?

Lessons learned... mistakes...hints... tips?

I would do it like OlyWaXJ with bent arms so that they tuck inside the frame rails. He posted pictures recently, I think they may all be in the "XJ on a frame" thread.

I am planning on mounting mine to the frame rails. The spot is the exact same spot I had my long arms attached. Everybody warned about hanging them up on the brackets, but I never had any problems with hanging up, so I am doing the simple and easy way.

so what you plan on using the stock Ford spring bucks on the axle ?what is the axle out of an F150?placing the coils on the stock bucks on a full size axle isn't the best solution.its the cheap solution thats for sure but not a good one.if you do it this way you are placing the coil on an angle .this is also going to causing binding on the spring post under compression

The easiest would be to just keep the arms straight & build mounts onto a cross member. This also gives the arms some triangulation to the front end that may reduce some stress on the track bar. The arm will also help protect your front drive shaft by running directly under it. Clearance wise, you want to tuck the mounts up at least flush with the cross member. The catch 22 to this is the higher you raise your mounts up the worse your caster gets. You can correct caster with "C" bushings up to 7 degrees. I see little to no reason to mount the arms up flush with the frame rails if you're still going to have the cross member hanging below.

In the trash can!


hinkley

With the arms attached at the axle find where they want the frame mounts to be - this will free them up alot for better articulation. I ended up bending my arms upward for better castor angles and built a crossmember mounting them inboard of the frame rails.

Nice, Mark..... :spin3: :doh: :looser:

Assuming you are using a full width HP44, the ford stock location will line up along the inside of the framerail or just a hair inside. I chose to pull them a bit wider and mount them under the rail (yes, there is enough movement in the C bushings to allow it). I have seen the arms extended 6 to 8 inches using tube, which placed it inside the framerail and about at the tranny crossmember (manual tranny that is). However, unless the arm is bent inward it will likely hit the frame.

FarmerMatt in 100% on caster. Mine are under the rail and I am running a 7deg bushing. This gave me steady steering feel and good return to center. Radius arm setups tend to be anti-wobble, so you can go less on your caster, but you begin to lose you return to center.

I have yet to smash my mounts or have them in the way for any reason. Having the arms pulled out the meet the frame does decrease steering a bit as my 35" tire will rub a bit on tight turns. I felt that this was ok to get around the difficulties of fabbing/fitting a forward crossmember or custom tranny crossmember and extend the arms.

dirtclod said:

Nice, Mark..... :spin3: :doh: :looser:

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hinkley

Mark Hinkley said:

In the trash can!


hinkley

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is where you'll find Marks sense of humour...:wierd:

FarmerMatt said:

is where you'll find Marks sense of humour...:wierd:

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I thought that was in the gutter!

hinkley

Mark Hinkley said:

I thought that was in the gutter!

hinkley

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No, that's your mind (what little there is of it)

On a side note, the second I saw the title to this thread I was thinking -IN THE JUNKYARD!
:wave:

I extended my F150 arms out 4.8 inches with 1.5" .25" wall DOM, and moved the axle forward at least an inch, which put the arms just inside the framerails. I did have to make a x-member (one in pic was a VERY rough mock up) which was a few inches further back than the stocker.
As it is now, my Re joints hang just a little lower than the plane of the framerails. I would have mounted them higher, but I had already set the pinion angle and radius arm angle and didn't want to futz with it anymore. If I was going to do it again I would set the radius arm angle to match the pinion angle exactly, which would point the pinion a few degrees up, and mount the radius arms inboard nicely when extended out with tube.

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FarmerMatt said:

The easiest would be to just keep the arms straight & build mounts onto a cross member. This also gives the arms some triangulation to the front end that may reduce some stress on the track bar. The arm will also help protect your front drive shaft by running directly under it. Clearance wise, you want to tuck the mounts up at least flush with the cross member. The catch 22 to this is the higher you raise your mounts up the worse your caster gets. You can correct caster with "C" bushings up to 7 degrees. I see little to no reason to mount the arms up flush with the frame rails if you're still going to have the cross member hanging below.

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Matt,
I'm a little confused. Shouldn't the mount of the radius arms happen first. Then the pointing the pinion at the TC. Then checking caster and possibly cutting and turning the knuckles. This progression makes sense to me, but I have not done this before the and the axles are sitting on the floor of the garage waiting for winter and me to figure out my design. Please correct me if I am going about this all wrong.

Matt

hadfield4wd said:

Matt,
I'm a little confused. Shouldn't the mount of the radius arms happen first. Then the pointing the pinion at the TC. Then checking caster and possibly cutting and turning the knuckles. This progression makes sense to me, but I have not done this before the and the axles are sitting on the floor of the garage waiting for winter and me to figure out my design. Please correct me if I am going about this all wrong.

Matt

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I don't think there is a right or wrong way to do this as long as you get the results that you want. The order in which I did mine was to first set the front end under the rig with tires mounted. I jacked the front end up to where it would best fit in the wheel wells fully compressed. Here I took note of clearances, meassured for bump stops, shocks, & generally planned out where everything would need to go. I than turned to the cross member & built it without mounts. Mounted the cross member to the rig & ran string line from the arms straight to where they lined up on the cross member. This showed where the mounts needed to be lined up with & at what angle to cut the mounts. The mounts were built & welded in place on the cross member. I than turned to the arms & measured hom much they needed to be legthened to meet those mounts. Mine ended up being somewhere in the neighborhood of 9". Now I finally get to pull the front end back out & build the arms. Once arms are built I mount the arms back up & connect them to the cross member. Here you get to start playing with trackbar, steering, shocks, springs & probably about a thousand other little things. I wasn't worried too much about caster until I got everything else in place knowing that I could adjust it with "C" bushings. Different front ends are designed with different caster in stock config. My EB low pinion 44 seems to have plenty caster even with the lift I run with stock rubber "C" bushings. The 78 high pinion 44 that I run in my CAT was a different story. With my radius arms mounted up past flush with the frame caster & pinion angle became issues. I had to put a corrective bend in the arms along with running 7 degree "C" bushing to bring the pinion & the caster back. The pinion was the biggest problem with issues of it wanting to beat the heck out of the exaust...

FarmerMatt said:

The pinion was the biggest problem with issues of it wanting to beat the heck out of the exaust...

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Same problem here. My nice borla now belongs in a scrap heap. How did you get around it?

Lucas said:

Same problem here. My nice borla now belongs in a scrap heap. How did you get around it?

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I rerouted the exaust around the front of the oil pan, TJ style.