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averagef250
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Post by averagef250 »

OK, some great news! Did some real careful measuring with the closed knuckle and the 78-79 axle side by side and if I build the new axle to 67.5" width there's the exact, perfect length of axletube to fully press the new "C"s on and weld them just like factory. No one will ever be able to tell it wasn't a factory axle when it's done. I'll need custom axles made or resplined to fit the narrow width, but everything should work out if I can get a working axle seal and figure out the kingpin angles.

Oh, and one more brain buster question- Why is it that the driver's side lower shock mount that's welded to the axle housing is only 2" long on 75 and earlier F-250 4x4 front axles and on 76-77 axles it's around 4" long and the upper shock mount is moved back to the next set of frame holes? Doesn't appear to be any clearance issues with the shock and steering arm on the early trucks. I don't see why they changed it and wondering which shock bracket I should go with.

Thanks again. I know you guys want to chime in any second now.
1970 F-250 4x4 original Willock swivel frame chassis '93 5.9 Cummins/Getrag/NP205/HP60/D70
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Post by averagef250 »

I'll just go ahead and answer all my own questions here I guess. After tearing the drum 60 down to it's bits, more good news, the standard 35 spline 60 axle tube seal fits perfect.

I think I've got the kingpin thing figured out as well. The '74 drum 60 front has the exact same kingpin angles as a '77 Dana 44 6CF and a '70 44 6CF. Seams to reason that the highboys all have the same kingpin angles. I feel pretty confident I'll get good results by exactly duplicating the closed knuckle angles with the new open knuckles.

Also, if it weren't for the drum brakes and tiny axles I'd have to say the closed knuckle 60 is pretty well put together. They actually come apart faster than a kingpin open knuckle 60.
1970 F-250 4x4 original Willock swivel frame chassis '93 5.9 Cummins/Getrag/NP205/HP60/D70
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Post by 460 crew »

averagef250 wrote:
Oh, and one more brain buster question- Why is it that the driver's side lower shock mount that's welded to the axle housing is only 2" long on 75 and earlier F-250 4x4 front axles and on 76-77 axles it's around 4" long and the upper shock mount is moved back to the next set of frame holes? Doesn't appear to be any clearance issues with the shock and steering arm on the early trucks. I don't see why they changed it and wondering which shock bracket I should go with.


Do the newer axles have a tighter turning radius? If they do the arm would come further in towards the shock mount. So they'd have to move it back a little. Seemed like my crew turned tighter with the D60 front axle than it did with the original close knuckle 44, might have just been the stops?
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Post by heep70 »

Doesn't ARB have a big part in that 35 spline D44? I have been reading about that conversion.
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Post by 72hiboy4x4 »

Do the newer axles have a tighter turning radius?


I know that the turning radius on my '72 SUCKS! :lol:
Thanks a lot, Pat! Now I'm thinking that I may need a newer axle just to be able to turn it around on the trails. But then, I guess power steering wouldn't hurt, either!
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re: For the axle gurus-

Post by 460 crew »

:lol: :lol: Turning around on the trails. I just said it might turn sharper but no promises of turning the bus around on a trail. PS is my #1 recommendation over anything except for the maybe disk brakes. I need to twin stick my 205 and get the e brake cables on seperate levers so I can lock them up and throw it in front wheel drive only and it can drag itself side to side on a pivot :hmm: Hey I can dream. :lol:
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Post by averagef250 »

Don't know much about the 35 spline 44 stuff. I was driving by my gear man buddies place with the old closed knuckle beast in the back of my truck so I pulled in and showed off my fresh kill.

We BS'd about how I was going to build it and he mentioned the conversion seal as a possible solution.

I'm not sure if there's a difference in turning radious or not. I have a 77 6CF HD 44 sitting on my shop floor, but it's in 50 pieces and the balljoints are out of it which makes it pretty hard to guestimate how far the knuckle will turn.

I wouldn't expect the turning radius to be much tighter in the newer highboys considering the 73-up trucks were 4" longer and went to a much wider rear axle which makes a worse turning radius and both front axles use U-joints which have a pretty solid limit of how far they turn before "pop". Or maybe my thinking is wrong. Maybe Because the trucks got longer and wider the front axle was made to turn tighter to compensate? A friends got a 77 F-250 4x4, but it doesn't run or I'd go test drive the turning radius. He's been deep in the midst of a 460 conversion for the past 5 years or so.
1970 F-250 4x4 original Willock swivel frame chassis '93 5.9 Cummins/Getrag/NP205/HP60/D70
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Post by pat67shorty »

Since you're local... I think you will find more axle knowlegable people on www.nw-wheelers.com. I'd post this in the tech section and see what they have to say.
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Post by averagef250 »

Wanted to update this thread now that axle is done. Maybe somebody else will want this info some day.

The kingpin angle front-back is always 4 degrees. For Fords it's simple. The kingpin is perpendicular to the spring pad as the spring pad sits at 4 degrees in any stock truck.

The shock mount is longer on 76-on disc brake front axles because the steering arm is longer. The steering arm is longer because the entire axle is 1.5" wider. The axle is 1.5" wider because open knuckles and disc brakes require the use of 3/4" more axle tube than closed knuckle stuff (I think it has to do with the bigger knuckle joints they ran). Ford made the entire axle wider instead of just moving the "C"s inward on the tubes because if they did, it's mess with the alignment of the shock mounts.

I had to shorten a 78-79 60 steering arm 3/4" and had to shorten the tie rods 1.5". Other than that every thing is beautiful. The axle looks and works perfectly and the tires don't stick out.
1970 F-250 4x4 original Willock swivel frame chassis '93 5.9 Cummins/Getrag/NP205/HP60/D70
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