76BFH I know that we can use them on the 3/4t but that's only cause Ford could and it was another option to the more expensive d60. If they could have figured a way to use the same one on all three and saved money as well as not significantly loose strength you bet they would have. But we still have not answered the original question. Is there any significant gain in a d60 ball joint (and only the upper at that, as that is the only one that would fit without modifying the knuckle ear).
Guess you could use the lower and ream the lower hole on the C to accept the larger diameter taper and stud. But is getting to hard into this. I am thinking that the d44 and d60 upper is exactly the same in strength, the lower probably not so as the d60 is listed as being able to tow more so strength has to be more.
If anyone can disprove this then I will listen with an open mind.....76 those slots are looking real nice after some polishing, Thanks man....Mo
Dana 60s have a larger knuckle (and taller) and inner-C casting than do 44s, along with larger bearings. The ball joint is not where the strength issue lies with regards to weight-carrying capacity. The same ball joint farther away from the axle centerline will be stronger.
Again, there is really no gain in modifying the D44 to use different ball joints as they aren't the weight failure point regarding load capacity. When the axle is loaded, there is a downward force pushing the ball into the cup in the balljoint with a minor inward component force due to king-pin inclination (aka scrub radius).
The weight rating comes with the axle tubes, spindles and brakes. This is why a 3/4ton D44 is only different than a 1/2ton D44 insofar as brakes and wheel bearings. The weakness is still in the physical knuckle castings and axle tubes.
My experience with broken ball joints is that the uppers break sideways from too much turning force, a broken stub shaft and already loose ball joints. When that happens, the ball joint usually takes the knuckle out with it. It's rare to see them break from overloading. The axle tube will usually bend before the ball joint breaks in that kind of load.
So in short Mo, save your effort and use a Dana 44 ball joint. I'm running a D44 locked on 39s in a 4600lb GPW with 351, ZF and Dana 300 and haven't had one spit out the side from beating on it.
-And it's good to see those wheels have found a new home!