Any U-Bolt Flip Axle Tube Failures?

Has anyone seen an axle tube failure from a u-bolt flip kit? I'm debating on what to use for my 63 swap. Proper square u-bolts with enough thread are proving hard to find, but u-bolt flip kits are readily available. With the rather thin Tacoma axle tubes, my worry is that the stress concentration from the u-bolts directly on the tube may cause a failure point vs the distributed load from the plate.

 

cant you get a Co. like Alcan in your State to make you some? https://www.alcanspring.com/

 

I've never heard of anyone crimping an axle tube with a flip kit. They have been around for years. Seems like if this was happening at all, you would find cranks always warning about making this mod on a trail rig. The bottom of an axle is usually in tension, so that probably has a role in lessening the risk of this.

 

On Gen 1 axles they usually crack out on the corners of the spring pads on the top of the housing.

https://www.tacomaworld.com/threads...ffroad-what-cracks-next.631359/#post-21655265

https://www.tacomaworld.com/threads/so-you-push-your-1st-gen-offroad-what-cracks-next.631359/

 

I don't think there is anything "usual" about what the vehicle in the linked threads is subjected to. I would speculate that the limit strap mount is also potentially playing a role here, every time the wheel is suspended in the air violently.

 

On my 88 that I SAS with and 85 front axle had a u bolt flip kit on it. I was younger and didn't do much my torque specs and managed to crack the housing on the passenger side due to the ubolt being torqued down too tight. It created either a weak spot or the hair line fracture itself... So yes, it can be done but if the ubolts are torqued correctly it shouldn't be an issue.

 

That's similar to the first time I ever considered tube failure from a u-bolt to be a possibility. It was from a passing reference on some YT channel about people over-torquing u-bolts and causing the axle tube to yield. That seems to be very uncommon though. Ordered all the parts to switch over from Ruffstuff, it doesn't seem like it is an issue if u-bolt torque is correct.

 

My fracture was on the passenger side inner ubolt area. As you can see it's a strange place to have the ublot b/c it doesn't exactly sit flush to the axle to start with due to the diff housing curve. Not my pic, but a clear pic of where the fracture would occur. On a rear, I'd say the chances of it happening would be even less.