Broken axle shaft

if i do upgrade to the 30 spline shafts and locker do i need it to be setup again? Or can I unbolt the ring gear from the true trac and install it on the new locker and keep the shims in the same spot?

I think my question got lost in the shuffle but can anyone let me know if its possible?
 
I think my question got lost in the shuffle but can anyone let me know if its possible?
It's possible but you'd have to check the backlash afterward. Measure it before & after the installation. If the backlash is still ok you're done. If the backlash changed enough, you'd need to shim the carrier a little left or right to get the backlash back in spec. This is a relatively minor thing to do, but there's a chance you wouldn't have to.

This is how the backlash (how much the carrier can be rotated) is checked... that gauge is not expensive, you can even get it from Harbor Freight Tools. This pic is from my 5.38 gear installation.
Checking-Backlash.jpg
 
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It's possible but you'd have to check the backlash afterward. Measure it before & after the installation. If the backlash is still ok you're done. If the backlash changed enough, you'd need to shim the carrier a little left or right to get the backlash back in spec. This is a relatively minor thing to do, but there's a chance you wouldn't have to.

This is how the backlash (how much the carrier can be rotated) is checked... that gauge is not expensive, you can even get it from Harbor Freight Tools. This pic is from my 5.38 gear installation.
View attachment 92902

ok sounds good thank you for the help
 
Not stupid, just some ignorance. In their natural state, both 4340 and 1541 are the same hardness. Both suffer the same fate if used as a shaft in that condition in that you will see them do what happened here, just twist off.

Heat treatment is what changes the properties of the material to give it properties we desire or need.
Both can be brought up to be hard enough for a bearing to ride on the surface. The issue is when that is done to 4340, that hardness goes all the way through the material because it is a through hardening alloy. Unless you are a talented heat treater, you won't be able to draw the core back down to be softer to add ductility to the shaft and it will be very brittle. 1541 is a surface hardening alloy so it responds well to bring the surface and a short distance below that up to bearing surface hardness without removing the ductility.
Thank you. I'm an engineer who deals with this somewhat, but my education was all in soil mechanics, not materials. We make pressure vessels up to 60,000 psi and load frames up to 1 million pounds. I can handle most of that, but we do have a guy who knows the steel properties and behavior better than I do. Of course as a typical engineer i need to ask a lot of questions and understand what is really going on. Thank you.
 
Not to flog a dead horse, but for clarity, what should a Jeep owner do if they knowingly purchased 4340 axles in the past XX months/years (they are literally everywhere, from many vendors, surely they aren't all falling apart of suffering failures such as the extreme bearing load pic earlier)? What of all the Dana 35 4340 axles being advertised this very minute, are they all ultimately garbage?
If someone has them in their Dana 35 are they running a ticking time bomb or are they no better but similarly not necessarily any worse off than having OEM axles presuming that they haven't failed already (such as the OP's did)?
Inquiring minds are curious...
 
Not to flog a dead horse, but for clarity, what should a Jeep owner do if they knowingly purchased 4340 axles in the past XX months/years (they are literally everywhere, from many vendors, surely they aren't all falling apart of suffering failures such as the extreme bearing load pic earlier)? What of all the Dana 35 4340 axles being advertised this very minute, are they all ultimately garbage?
If someone has them in their Dana 35 are they running a ticking time bomb or are they no better but similarly not necessarily any worse off than having OEM axles presuming that they haven't failed already (such as the OP's did)?
Inquiring minds are curious...
@Jerry Bransford posted the pic. Maybe he can speak in detail about this and answer your questions.
 
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I don't want to start a whole new thread, so I'll just ask in this one since it's about axles. I'm looking to upgrade my Dana 35 and was wondering how I can tell if the axle is capable to do a "super" upgrade. From what I've been reading so far, and it a LOT, it's for Dana 35's with the C-clip, which is what I believe I have. 1999 TJ SE. Any help would be greatly appreciated.
 
I don't want to start a whole new thread, so I'll just ask in this one since it's about axles. I'm looking to upgrade my Dana 35 and was wondering how I can tell if the axle is capable to do a "super" upgrade. From what I've been reading so far, and it a LOT, it's for Dana 35's with the C-clip, which is what I believe I have. 1999 TJ SE. Any help would be greatly appreciated.
Your Dana 35 is eligible for a Super35 upgrade. The Super 35 kit will come with 30 spline shafts and a locker. Have them regear when they are in there to save some money.
 
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May be another dumb question, do I need to change my front Dana 30 splines to match the rear as well. I read that I don't need to, just the gears in the axles have to match if I change them?
 
May be another dumb question, do I need to change my front Dana 30 splines to match the rear as well. I read that I don't need to, just the gears in the axles have to match if I change them?

Your fronts are 27 spline. Unless you swap unit bearings to accept a 30 spline outer shaft as well as the carrier. Stick with the 27s. Far more abundant and plenty strong when upgraded to chromos.
 
May be another dumb question, do I need to change my front Dana 30 splines to match the rear as well. I read that I don't need to, just the gears in the axles have to match if I change them?
Nope. The shafts spin the same speed as the carrier. The speed at which the carrier spins is determined by the ring and pinion gear ratio.

You can upgrade to 30 spline inner axles if you install a locker or another carrier that is designed to accept 30 spline axles. This modestly increases axle shaft strength, and is usually not necessary. (The outer stub shafts always stay at 27 spline unless you convert the hubs, which is a lot of cash and work.)

Regardless of whether you stick with 27 or go to 30 spline front axles, you’ll probably eventually want chromoly shafts if you go any larger than 33” tires, or perhaps even on 33s. These can be installed at any time before or after the regear (unless you convert to 30 spline, at which point you will need to install the shafts at the same time as the new locker/carrier).