PEAK PUTTERS

The Rubicon's OE shafts are carbon steel 30 spline shafts. There is a major boost in strength available by upgrading to Superior Axle's Evolution Series 30 spline axle shafts which are made from a hardened alloy with rolled (not cut) splines.

Don't bother upgrading the front axle u-joints, they are plenty strong as is unless you are doing some just plain crazy stuff. The reason the OE u-joints fail if pushed too hard is not due to weakness in the u-joints themselves. The root cause of front u-joint failure is actually usually because of the ears that hold the u-joints failing on the unhardened carbon steel axle shafts the factory installs.

The "ears" on the inner/outer axle shafts that hold the u-joints are unhardened. As such, when you put much stress on the front tires (especially when the steering is turned very far to one side), those ears stretch or fail which then spits out the u-joint. That allows the now free u-joint to smash into one or more of the four ears that used to hold it, breaking the u-joint. Replacing the front 30 spline axle shafts with hardened alloy 30 spline axle shafts like Superior Axle's Evolution Series will prevent that from happening by their ability to hold onto the u-joints under stress much more reliably.

After breaking my passenger-side axle shaft ears and u-joint while doing Sledgehammer years ago, I replaced my front axle shafts with Warn's hardened alloy axle shafts (no longer sold) and even doing tougher trails after that, I had no more front axle shaft or u-joint failures. That was with Spicer's OE size 5-760x u-joints up front.

So don't bother upgrading your front u-joints, upgrade your axleshafts. Then if you get into some crazy-tough stuff later on (REALLY stupid-crazy hard) and start breaking u-joints by themselves, you can go to CTM's uber-strong u-joint. But at $160 each, they aren't for the faint of heart.

OldGreen wrote:Having typed that, you will then run the risk of breaking your ring and pinion if you decide to do a full lock turn in a parking lot with your front locker on

tobyw wrote:Having gone through more than my fair share of front axle shafts on various rigs, I'm still not of a mind that upgrading to chromos really offers any serious advantage IF you have access to factory replacements at a reasonable cost. That is simply because, in my experience, most front axle shaft failures are at the u-joint ears, which are NOT covered by warranty. That is why I went with RCV's on the JK; factory spares were not available anywhere and RCV was the only one that offered an unconditional warranty. As I've said before, that may have changed between now and then, but the marginal gain in strength of treated chromo shafts at the u-joint ear is not the holy grail savior. To address the issue on stock shafts, simply tack weld the u-joint cap to the ear, or take it one step further and weld on some appropriately sized washers/flat stock to tie it all together. Old school tech that works. Oh, and try not to perform 4k rpm neutral drops with the wheels cranked in deep snow/mud

TJDave wrote:Awesome! And they came with the joints already installed? Excellent.

I'll be getting me some when working again. Oh, wait. I start Monday!

iaccocca wrote:Thanks for everybody's input. For those voing for stock axles, there is something you should know... these come with a sticker.