Sorry about your bad luck Tom.

I played briefly with rear axles back when I had the F350. I found out that there are as many flavors of Dana axles as there are stars in the sky. It's not something I had fun with. You have to get under the truck and get the exact numbers and markings off the rear axle, then you know what you've got. You might be able to find a replacement or at least discuss the issue online with a forum like this but dedicated to Trucks.

Hopefully the fix is simple for you but I suspect it won't be. I think the primary cause of failure is most likely the 5 letters that are found on the tailgate of your truck. We drive those at work and I'm frequently amazed at the utter crapiness of the vehicle on a regular basis.

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-livin' in the terminally flippant zone