This is the second RH Axle Tube I've have replaced in the last 4 months and they are hard to come by used and expensive as hell new. Before I replace the front diff/axle for a second time I'd like to figure out how/why they're cracking.

After I replaced the first one, I kept the truck on city pavement with intermittent highway travel and about 20 miles of gravel. The only thing each incident has in common is me and two nasty snowstorms. I drove on the highway during each of these storms and took it in and out of 4x4 repeatedly (and yes I was going fast but I don't remember how fast - it may have been above the suggested 55mph for 4x4 shifting a couple of times).

My current theory is that I torqued the axle tube/housing forward while getting into 4x4. To be specific, the tube cracked on the far right hand end (closest to the tire) under the frame mount. It looks like the rest of the tube rolled forward while that point remained stationary.

On the other hand, there shouldn't be play in that diff because it's mounted at 6 different points so I'm at a loss. Thoughts?

Also, does anyone know if I can get this welded back together? I think it's cast aluminum but I'm not 100%.



(The axle tube is part #15)





It may be hard to tell but the piece in the middle is peeling out slightly.





This is the top view of the previous photo.





As you can tell however, the crack does not go all the way around the front or bottom of the tube....yet.

 

That's pretty strange to happen twice. I'm going to take a stab in the dark here;

Your CV axle on the passenger side; are the boots intact and does everything move freely? With your wheel and control arm moving up and down and left to right with the suspension and steering, if for whatever reason your cv half shaft starts to stick / not move freely, you will be exerting forces on the axle tube.

Another (less likely) thing to look at might be your front driveshaft. It should be splined with a dust boot. Unbolt one of the u-joints and make sure it can still move in and out (telescopically), and that it isn't seized.