RedneckJeep

I got money says you're safe. The break was well away from the ring and pinion......but you never know. Better to be safe than sorry.

chuck45

Your theory may sound good to you but it is wrong. I've talked to nobody who said a D44 axle would give at anywhere near 2925; 7000 is the floor for a stock D44 shaft. The other three wheels could turn quite freely; and did after the rear axle broke. When you are all locked up and nothing is turning the one that is in the bind is providing all the resistance. You could do the same thing with the Jeep jacked up in the air with three wheels able to turn freely but only one restrained; say chained up to a giant torque gauge that could read torque (easy to do, we do it at work). None of the other wheels will turn and all the torque output will be read on the torque gauge. Until the point the axle breaks and then the torque will be deliverd to the other wheels.

NH4X4

should be warranty... I hope

ThinkMud

sorry to hear about the break, but awesome it's getting replaced! i guess I need to invest in some soon too... man my list keeps getting longer and longer....

ronjenx

chuck45's example is correct. However, in jkkat's incident, it's probably not as simple as chuck45's math would indicate. After all, it's a dynamic situation, with all 4 tires being in the mud.
It may have been more like this:
All 4 tires in the mud, with one being harder to turn than the others, added up to more resistance than the engine could turn.
The weak link broke, and suddenly all the torque was going to only 3 tires, which provided significantly less resistance. Therefore, the engine could spin them.
It's too hard to say at what torque the shaft failed.

Was the locker the OEM Tru-Loc? If so, I would say it was stronger than most people give it credit for.

2climbbig

For the long (inner)shaft you want flex. So the nipple look is the right indicator ( your friend would be correct with that). For the outer shaft, you don't won't get that flex as the shaft is not long enough to provide that kind of give. A nipple on the outer shaft is an indication that the metal is too elastic for that application. That elasticity would apply stress to the splines.... not a desired trait. You inner shaft should act as the spring.

jkkat

Yes, Stock lockers.

third broken stub shaft for RubyDoo, first 2 were stock shafts and always happened in reverse too.

jkkat

We found this when we went to replace the stub shaft.



Many thanks to Dave and his Dad @ Northridge for doing all the hard work and the warranty stuff.

chuck45

My opinion on the stock locker is mixed at this point. As far as I can tell both my lockers are working and behaving exactly as they should. However when I talked to Steve at Moab 4x4 Outpost he said the lockers often fail when an axle shaft breaks. He showed me one that had failed and it looked like where the axle splines slide into the carrier had cracked in multiple place and had expanded. It must happen often enough that he keeps Rubi lockers in stock.

Barney Bros, my local 4x4 shop that did my gears, told me yesterday that they've had to replace several Rubi lockers after axles broke.

I had to pull my front carrier out to remove the stub and everything looked good. I seem to be developing a noise in my rear axle. A stethoscope indicates that it's probably the pinion bearing going south. Barney Bros is going to pull it apart next week to replace the bearing and while out they're going to check out the elocker for me.

From what I can gather it seems that taking out the Rubi locker seems more common with stock shafts than with CM shafts. I have no idea why or how this could be. Could it be that the stockers are cut splines and the CM shafts are rolled splines?

All I know is that I'm going to take it a little easy until the container with ARB lockers for the Rubi axles arrives. I won't mind replacing the locker with an ARB; but it would really frost my ass to have to buy a factory unit.

2climbbig

That is a great picture... Sorry, not that what happened to you is great. Just that a picture is worth a 1000 words. Imagine if that shaft was so elastic that it could bend that much and return back to its normal position. How much stress would be constantly applied to the splines on the hub. You would be constantly damaging the hub, if your outer shaft was too elastic. Hence my point on not wanting a nipple on the short shaft.

Sorry, I get all geeky when talking about engineering. Can't help myself... did it for a living.