The super 60 axle is wider and will allow for a sharper turn but probably not as tight as with coil springs.
The radius arm brackets are a lot of metal to remove for the axle tubes, my concern would be worping a axle tube during all that cutting and welding.

 

The way the fixture or jig is set up for these, warping shouldn't be an issue whether widening or narrowing. Not an expert - just saw the process in a couple of videos.

 

I don't understand. Unlike the rear leaf springs that suspend the truck from hangars outboard of the frame, the front leaf springs are suspended directly underneath the frame. The front leaf springs are no more in the way than the frame itself. The radius arms of the coil suspension originate in the same anchor location vector on the frame as the aft shackle of the front spring.

I'm not aware of a single medium duty or heavy duty truck that has coil springs upfront, and they all have 50 degree wheel cuts. Ford's F-53 and F-59 chassis have 50 degree wheel cuts, with leaf springs. GM's 2004-2009 Kodiak and Top Kick C4500/5500 had leaf front springs, as did their 4x4 counterparts. The 2019 versions, now called Silverado 4500HD, 5500HD, and 6500HD, whose chassis is built by Navistar, who in turn is selling their own branded version under International's brand called the CV series, has an upper 40's wheel cut in the 4WD version, with front leaf springs. I think the older C4500/5500 4x4's might be a fairer comparison to the 37" front frame rail widths of the Fords, due to the wider frame width in the GM built 4500/5500 series than the new 34" International built series, but if the issue boils down to frame width, the frame width is no different in a coil sprung Ford versus a leaf sprung Ford.

Therefore, I do not understand how the coil spring package is contributing to the wider wheel cut.

I do understand how moving the knuckles further outboard away from the frame, as the Super 60 does with longer axle tubes, creates more clearance for a wider angle of wheel cut.

 

my tires run my leafs but dont rub my frame, im no scientist tho.

 

The leafs hang below the frame. The leafs are a few inches above the horizontal plain of the center line of the tires. When the tire is turned it is close to the farthest distance from the center line of the axle, so it would make contact with the leaf. With coil, the frame is still higher but now there is no leafs hanging down in that area so the tire can rotate farther. Clear as mud. If you go look at a leaf sprung vs coil sprung it should make sense.

 

The above scenario is described as if the axle doesn't move up and down. As if clearance measurements are only determined statically, as the vehicle sits when parked.

There is 4" of jounce travel between my spring caps and the jounce bumper on the frame. My stock tire diameter is 32", half of which is 16". Measuring 16" back from the shock tower, the frame height is 21". Subtracting 4" jounce travel from 21" frame height leaves a 17" frame height at full jounce. The tire's width is 9".

The Pythagorean Theorem states that a^2 + b^2 = c^2 for a right triangle, which we find looking straight down at the tire from above, with a known radius of 16" (leg a) and a known width of 9" (leg b") and where we want to find the length of C (the hypotenuse) so as to identify when the inside tread corner of the tire could potentially strike the frame or leaf springs or radius arm, at the tire's maximum diameter during full jounce. 256 + 81 = 337. Since these are squares, we want the square root of the result, which is 18.35, or roughly 18". And the frame is 17" off the ground at this point.

Now, whether the tire clears within the range of 16" to 18" depends on the actual pivot axis of the king pin, and the amount of inset or offset of the wheel and tire assembly rotating around it, but I think everyone would agree that Ford wouldn't cut it that close. Just one inch? That doesn't seem very OEM like to me. Now add in optional tires. 33" tires. 265's. Add in very mild aftermarket tires. 35's. The diameters increase to 17", without even taking into account the tread width, pivot axis, offset, or hypotenuse.

So I still see the greater wheel cut afforded by the Dana Super 60 axle in the chassis cabs resulting in the dramatically tighter turning radius being mostly a function of the wider track axle. The larger half shaft U joints contribute to reliability in the greater steering articulation. I don't see coil springs as that significant of contributing factor in wheel cut, when considering the full range of suspension travel that must be accounted for.

 

well, since this has become the all inclusive axle swap thread, are the 2017 and up axles the same dimensionally as the 05-16 axels? Are the radius arm mounts in the same place? The coil spring locator the same? My bet would be that the newest axels are slightly narrower.

 

I noticed the holes in my frame are 1/2" but the holes in my 08' radius arm brackets are closer to 9/16" or 14mm . did you guys inlarge the holes in the frame to match the brackets?

thanks!
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I noticed the holes in my frame are 1/2" but the holes in my 08' radius arm brackets are closer to 9/16" or 14mm . did you guys inlarge the holes in the frame to match the brackets?

thanks!

 

I did not enlarge any holes in the frame. I used flange head bolts with flanged lock nuts to cover any extra space in the hole around the bolt shaft.

 

I assume you feel that is adequate? I plan to use flange bolts as well..... Is this how flange bolts work? I'm not familiar with them... I was just concerned because of the size differences between frame and bracket holes...

thanks for the input! BTW..

 

All my bolts fit pretty snug in their new homes when I put the 07 brackets on, so I am not concerned at all. Not one has moved since I put them on almost a year and 27k miles ago. It is possible the 08 trucks used a 9/16 rivet in place of the 1/2 rivets on the 05-07. I have not measured them with a micrometer or anything.

The flange head bolts negate the need for washers. They are more stable in my opinion vs using a bolt and a washer. The locking flange nuts should be obvious as to why I used them over a lock washer. Far superior for such a critical joint.

 

THANK YOU! and just to confirm, i measured the 08' frame. the factory rivets are 1/2'' for the coil buckets and 9/16" for the radius arm brackets.. so yes different sizes depending on year...

also the 07' and newer radius arm bracket is a good option as it lines right up with the excursion frame (no need for spacer between frame and bracket) CORRECTION- I DID END UP USING A 1/4" SPACER . ONCE I DRILLED THE FRAME HOLES TO 9/16 AND TEST FIT THE BRAKET I HAD A 1/4" GAP BETWEEN BOTTOM OF FRAME AND BRACKET, SO SPACER OR WASHERS IS NECESSARY....

 

I had to replace the junk yard front axle hub/bearings yesterday. I did manage to get 34k miles out of them, so I think I did alright keeping them on when I did the install. I have to say...it is way easier doing hub bearings on these newer axles than the old 99-04 versions. Well...as long as you have the super heavy duty snap ring pliers. Took me 2.25 hrs to do both sides combined. It sure drives a lot nicer with the new hubs. Amazing the difference a new set makes.

So, 14 months in and 34k miles on the swap, and this was my first maintenance item I had to address. Remember to re-use the old ABS sensors in your new hubs, or you will get a constant ABS light and no ABS action when braking.

 

34K miles in 14 months! No grass growing under does tires.
Glad to see it's giving you good service.