RCV Axles (1 Viewer)

[Broski]

So after 3 years and countless hardcore wheeling trips on 39" tires my RCV both let go at the same time & both axles broke at the same place just inside the cage

The thing is that I was not even on a obstacle, there was no bouncing,hopping,shock load, nothing like that.
Just diff hung on the rear axle housing. Really this is where I was rear diff was hung up on the rocks in the middle of the picture & trail, my fronts were where the smaller rocks are filling the hole in the trail.

It is the first time in 8 years of ownership that I had a major brake on the trail.
This leaves me wondering why they both let go like that, was it fatigue ? 8 years of wheeling with 35s then 37s and now 39s
Are the 39s just to much for that axle ?
Defect in the axles ?
I always felt The 8" third would let go before the RCV
Don't worry about it, just put the new one's in and go wheeling

I did upgrade to the 300M axles 30 spline and 28MM instead of 26MM and 26 spline.

And no I have not been working on it Life has been getting in the way

 

[mudgudgeon]

The timing for both to meet go together is odd for sure.
But 8 years of harder wheeling in a fairly heavy rig, stuff is gonna fail.
Things fatigue, and fall at some point they were obviously both at their limit, one failed the other got a sudden shock load and failed too. Strange coincidence.

you've just upgraded, don't over think it. Run them.

Wheel, break, fix, repeat.

You gotta pay to play.

Guys running heavier axles in lighter buggies still have failures. At some point something is gonna break if it keeps getting stressed to is limits whether it's abused or not.

 

[mudgudgeon]

Years ago, a buddy showed me a slo-mo clip from King of Hammers of a buggy, on the limiter, front and rear locked, climbing a rocky slope. It really high lighted the torsional loading and unloading that happens in an axle.

You could see the wheels cycle through distinct phases of torsional loading/unloading of the axle.
wheel would spin rapidly for a few moments as they broke traction and the twisted axle unwound, then just spin. Then the wheel would stop spinning for a few moments when the tire found traction and the axle would load up, then drive forward, until it broke traction again.

4 district changes in wheel rotation was visible in rapid succession, over and over. I found it interesting, and it made me think 'no wonder these guys break axles'

 

[aztoyman]

I've changed broken axles on massive mining machines like haul trucks and there are safeguards built into the machines so the operators can't abuse them. They log events in the computers that can't be erased so we can go in and see if there was any intentional misuse or maybe a design fault that needs to be corrected.

Parts still fail. They do have a finite life expectancy. The aviation industry especially knows the expected life of components and strives to ensure they are changed out before expected failure. So does many industries actually. It's cheaper to do a planned rebuild on an expensive machine than to repair a catastrophic failure.

Everything has it's limits and nothing lasts forever. Your axles hit their limit. Like mudgudgeon said, one probably failed causing an overload on the other. You're not a reckless driver beating on your truck or they wouldn't have lasted as long as they have. The same can be said for the quality of the part. If they were defective, they wouldn't have lasted this long.