Gusseting The Inner Knuckles

[Goatman]

The contact surfaces of the axle tube and the inner c must be truly cylindrical and provide a press fit of about 2-3 thousanths of an inch. This will provide a stout mate between the two components, thus allowing the weld and press fir to share the loads seen on that location. Yes the ends are welded on the face as well as on the corner between tube and c, from the factory and any good axle builder.

Correct.....and your point is?

The inner C has to be heated to allow it to be pressed back onto the tube and put in the proper place...........at least when doing it in the garage, without a large axle press.

 

[Starboard M]

I also believe there is a reason they put the brace on the bottom. While the inner C on one side broke loose, the weld was cracked for a couple of inches on the very bottom of the other side inner C. That is very likely how the broken side started, and it would not have happened with those braces like Currie and other builders use.

Im curious as to why the brace should be put on the bottom of the axle tube. Wouldnt it have the same advantage as having it on the top? Or would the torque be applied differently?

 

[BrettM]

Im curious as to why the brace should be put on the bottom of the axle tube. Wouldnt it have the same advantage as having it on the top? Or would the torque be applied differently?

generally the forces are trying to bend the knuckle up and in, and the gusset is stronger in tension than compression. ideally a full axle truss would be under the axle, but for clearance reasons it is often put on the top. many baja/pre-runner trucks truss the bottom side since clearance isn't as much of a concern for them (vs. rockcrawling) and bending housings is a real problem.

 

[Goatman]

Im curious as to why the brace should be put on the bottom of the axle tube. Wouldnt it have the same advantage as having it on the top? Or would the torque be applied differently?

The forces against the knuckle would try to pull apart the weld at the bottom of the inner C, and the weld is weaker with forces pulling against it than it would be pushing against it. Plus, the inner C has a lip that sets against the end of the tube, so it can't be pushed in at the top. Nearly all the potential for coming apart is on the bottom.

While the inner C on one side broke loose, the weld was cracked for a couple of inches on the very bottom of the other side inner C. That is very likely how the broken side started, and it would not have happened with those braces like Currie and other builders use.

 

[Jeff 98XJ WI]

So, goatman is back from oblivion? What's this lip on the inner C that sets against the axle tube? I didn't have any lip that I can recall. I believe I could have pounded the inner C all the way on to the tube till the tube was sticking out from the inner C.

What are your thoughts on running a nice bead around the end of the tube and the inner C portion that sits right behind the u-joint? Other than making it much harder to remove the C, I don't see where there would be a problem with this AND it would effectively double the weld surface holding the inner C to the axle tube. One would want to chamfer the end of the tube and the edge of the inner C before welding it up, but again, it seems to me that would really help hold the inner C on. I'm not sure if Cyrus was saying that this is the way the factory does it, but I KNOW that when I removed the C's from my D44 front axle, there were NOT any welds on the end of the tube to the inner C. The only welds from the factory are between the inner portion of the inner C and the tube. Jeff

 

[cyrus]

I'm not sure if Cyrus was saying that this is the way the factory does it, but I KNOW that when I removed the C's from my D44 front axle, there were NOT any welds on the end of the tube to the inner C. The only welds from the factory are between the inner portion of the inner C and the tube. Jeff

the three D44's I've narrowed were welded on the inside and outside of the inner C. these were all out of 77-79 vintage fords.

I have a freind who workes for AAM. there's are all welded on the inner and outer edges of the c's, at least all the heavy stuff they build.

 

[Goatman]

So, goatman is back from oblivion? What's this lip on the inner C that sets against the axle tube? I didn't have any lip that I can recall. I believe I could have pounded the inner C all the way on to the tube till the tube was sticking out from the inner C.

What are your thoughts on running a nice bead around the end of the tube and the inner C portion that sits right behind the u-joint? Other than making it much harder to remove the C, I don't see where there would be a problem with this AND it would effectively double the weld surface holding the inner C to the axle tube. One would want to chamfer the end of the tube and the edge of the inner C before welding it up, but again, it seems to me that would really help hold the inner C on. I'm not sure if Cyrus was saying that this is the way the factory does it, but I KNOW that when I removed the C's from my D44 front axle, there were NOT any welds on the end of the tube to the inner C. The only welds from the factory are between the inner portion of the inner C and the tube. Jeff

Well, you got me there, Jeff.........it must be age. You're right, there isn't a lip on the inner C, I haven't spent much time on the computer lately and my memory is fadding.

I see no reason that you couldn't put a bead on the outside of the tube and the C, but I really don't think you'd have to. Inner C's breaking off isn't a common thing, and I really do think that adding a gusset on the bottom is all the insurance that's needed. The weld bead on mine was small compared to the Currie axles that I checked out, plus I didn't have the gusset, and I'm running 37's and abusing the hell out of it with fast desert runs and jumps, plus plenty of fairly quick trail work. More evidence of the abuse that my front end gets is that I've broken the steering box off the frame, with the frame reinforced AND running a steering brace......broke two bolts and one ear off the box, didn't hurt the frame at all. I also just broke a sector shaft, which showed that it was already cracked about 40% through.

 

[jeep_87_cherokee]

yea i got a real example of why you SHOULD NOT jump your jeep cherokee [ha ha ha] and a real reason YOU SHOULD gusset your C's is what you are calling them, i refer to them as inner knuckles or knuckle yokes, my jeep got some air time once and that was all it need to bent the inner knuckle - it is bent so much that the outside edge of the tires aren't touching the ground. if you stand in front of it and look at both the front tires you can see it BAD they are leaning in so much at the top, its retarded, i gotta get a photo of it on here so you know not what to do to a stock front axle, next i'm gonna change the inner knuckles to dana 30 style off a CJ then i can put some 44 knuckles on and some high steer, just whenever you got the axle out and got the welder buy gusset the inner knuckles